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Document and Entity Information - USD ($) $ in Billions	12 Months Ended
Document and Entity Information - USD ($) $ in Billions	Dec. 31, 2018	Jan. 28, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	NORTHROP GRUMMAN CORP /DE/
Entity Central Index Key	0001133421
Document Type	10-K
Amendment Flag	false
Document Fiscal Year Focus	2018
Document Period End Date	Dec. 31, 2018
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 53.4
Entity Common Stock, Shares Outstanding		169,737,507

Consolidated Statements of Earnings and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Operating costs and expenses
General and administrative expenses									3,011	2,712	2,632
Operating income	943	1,172	817	848	672	829	864	853	3,780	3,218	3,277
Other (expense) income
Interest expense									(562)	(360)	(301)
Net FAS (non-service) pension benefit									1,049	699	611
Mark-to-market pension and OPB (expense) benefit									(655)	536	(950)
Other, net									130	136	44
Earnings before income taxes									3,742	4,229	2,681
Federal and foreign income tax expense									513	1,360	638
Net earnings	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Basic earnings per share
Basic earnings per share	$ 2.07	$ 7.15	$ 4.52	$ 4.82	$ 3.86	$ 4.31	$ 3.88	$ 4.41	$ 18.59	$ 16.45	$ 11.42
Weighted-average common shares outstanding, in millions	171.8	174.1	174.5	174.3	174.2	174.2	174.5	174.8	173.7	174.4	178.9
Diluted earnings per share
Diluted earnings per share	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Weighted-average diluted shares outstanding, in millions	172.6	174.9	175.4	175.4	175.5	175.3	175.5	176.1	174.6	175.6	180.5
Net earnings (from above)	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Other comprehensive loss
Change in unamortized prior service credit, net of tax expense of $19 in 2018, $35 in 2017 and $20 in 2016									(60)	(44)	(62)
Change in cumulative translation adjustment									(8)	(4)	(50)
Other, net									(6)	2	(1)
Other comprehensive loss, net of tax									(74)	(46)	(113)
Comprehensive income									3,155	2,823	1,930
Product [Member]
Cost of Goods and Services Sold									15,785	12,527	11,197
Revenues									20,469	16,364	15,080
Service [Member]
Cost of Goods and Services Sold									7,519	7,547	7,600
Revenues									$ 9,626	$ 9,640	$ 9,626

Consolidated Statements of Earnings and Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Tax expense on the change in unamortized prior service credits	$ 19	$ 35	$ 20

Consolidated Statements of Financial Position - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 1,579	$ 11,225
Accounts receivable, net	1,448	1,054
Unbilled receivables, net	5,026	3,465
Inventoried costs, net	654	398
Prepaid expenses and other current assets	973	445
Total current assets	9,680	16,587
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017	6,372	4,225
Goodwill	18,672	12,455
Intangible assets, net	1,372	52
Deferred tax assets	94	447
Other non-current assets	1,463	1,362
Total assets	37,653	35,128
Liabilities
Trade accounts payable	2,182	1,661
Accrued employee compensation	1,676	1,382
Advance payments and amounts in excess of costs incurred	1,917	1,761
Other current liabilities	2,499	2,288
Total current liabilities	8,274	7,092
Long-term debt, net of current portion of $517 for 2018 and $867 for 2017	13,883	14,399
Pension and OPB plan liabilities	5,755	5,511
Deferred tax liabilities	108	0
Other non-current liabilities	1,446	994
Total liabilities	29,466	27,996
Commitments and contingencies (Note 12)
Shareholders’ equity
Preferred stock, $1 par value; 10,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $1 par value; 800,000,000 shares authorized; issued and outstanding: 2018—170,607,336 and 2017—174,085,619	171	174
Paid-in capital	0	44
Retained earnings	8,068	6,913
Accumulated other comprehensive (loss) income	(52)	1
Total shareholders’ equity	8,187	7,132
Total liabilities and shareholders’ equity	$ 37,653	$ 35,128

Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 5,369	$ 5,066
Long-term Debt, current portion	$ 517	$ 867
Preferred Stock, par value	$ 1	$ 1
Preferred Stock, shares authorized	10,000,000	10,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	170,607,336	174,085,619
Common stock, shares outstanding	170,607,336	174,085,619

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net earnings	$ 3,229	$ 2,869	$ 2,043
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	800	475	456
Mark-to-market pension and OPEB Benefit	655	(536)	950
Stock-based compensation	86	94	93
Deferred income taxes	234	985	(60)
Changes in assets and liabilities:
Accounts receivable, net	202	(209)	46
Unbilled receivables, net	(297)	(422)	(211)
Inventoried costs, net	(37)	25	(53)
Prepaid expenses and other assets	(56)	(92)	(117)
Accounts payable and other liabilities	381	570	18
Income taxes payable, net	(258)	(157)	148
Retiree benefits	(1,083)	(946)	(375)
Other, net	(29)	(43)	(125)
Net cash provided by operating activities	3,827	2,613	2,813
Investing activities
Acquisition of Orbital ATK, net of cash acquired	(7,657)	0	0
Capital expenditures	(1,249)	(928)	(920)
Other investing activities, net	28	39	115
Net cash used in investing activities	(8,878)	(889)	(805)
Financing activities
Payments of long-term debt	(2,276)	0	(321)
Net proceeds from issuance of long-term debt	0	8,245	749
Net (payments to) proceeds from credit facilities	(320)	(13)	135
Net borrowings on commercial paper	198	0	0
Common stock repurchases	(1,263)	(393)	(1,547)
Cash dividends paid	(821)	(689)	(640)
Payments of employee taxes withheld from share-based awards	(85)	(92)	(153)
Other financing activities, net	(28)	(98)	(9)
Net cash provided by (used in) financing activities	(4,595)	6,960	(1,786)
(Decrease) increase in cash and cash equivalents	(9,646)	8,684	222
Cash and cash equivalents, beginning of year	11,225	2,541	2,319
Cash and cash equivalents, end of year	$ 1,579	$ 11,225	$ 2,541

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Common stock	Paid-in capital	Retained earnings	Accumulated other comprehensive loss
Beginning of year at Dec. 31, 2015		$ 181	$ 0	$ 5,329	$ 160
Impact from adoption of ASU 2018-02 and ASU 2016-01				0	0
Common stock repurchased		(7)	0	(1,548)
Shares issued for employee stock awards and options		1	0	(50)
Net earnings	$ 2,043			2,043
Dividends declared				(633)
Other comprehensive loss, net of tax	(113)				(113)
End of year at Dec. 31, 2016	$ 5,363	175	0	5,141	47
Cash dividends declared per share	$ 3.50
Impact from adoption of ASU 2018-02 and ASU 2016-01				0	0
Common stock repurchased		(2)	0	(371)
Shares issued for employee stock awards and options		1	44	(39)
Net earnings	$ 2,869			2,869
Dividends declared				(687)
Other comprehensive loss, net of tax	(46)				(46)
End of year at Dec. 31, 2017	$ 7,132	174	44	6,913	1
Cash dividends declared per share	$ 3.90
Impact from adoption of ASU 2018-02 and ASU 2016-01				(21)	21
Common stock repurchased		(4)	(34)	(1,225)
Shares issued for employee stock awards and options		1	(10)	(6)
Net earnings	$ 3,229
Dividends declared				(822)
Other comprehensive loss, net of tax	(74)				(74)
End of year at Dec. 31, 2018	$ 8,187	$ 171	$ 0	$ 8,068	$ (52)
Cash dividends declared per share	$ 4.70

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Significant Accounting Policies

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Nature of Operations

Northrop Grumman Corporation (herein referred to as “Northrop Grumman,” the “company,” “we,” “us,” or “our”) is a leading global security company. We offer a broad portfolio of capabilities and technologies that enable us to deliver innovative platforms, systems and solutions for applications that range from undersea to outer space and into cyberspace. We provide capabilities in autonomous systems; cyber; command, control, communications and computers, intelligence, surveillance and reconnaissance (C4ISR); space; strike; and logistics and modernization. We participate in many high-priority defense and government programs in the United States (U.S.) and abroad. We conduct most of our business with the U.S. government, principally the Department of Defense (DoD) and intelligence community. We also conduct business with foreign, state and local governments, as well as commercial customers.

On June 6, 2018 (the “Merger date”), the company completed its previously announced acquisition of Orbital ATK, Inc. (“Orbital ATK”) (the “Merger”). On the Merger date, Orbital ATK became a wholly-owned subsidiary of the company and its name was changed to Northrop Grumman Innovation Systems, Inc., which we established as a new, fourth business sector (“Innovation Systems”). The operating results of Innovation Systems subsequent to the Merger date have been included in the company’s consolidated results of operations. See Note 2 for further information regarding the Merger.

Principles of Consolidation

The consolidated financial statements include the accounts of Northrop Grumman and its subsidiaries and joint ventures or other investments for which we consolidate the financial results. Material intercompany accounts, transactions and profits are eliminated in consolidation. Investments in equity securities and joint ventures where the company has significant influence, but not control, are accounted for using the equity method.

Basis of Presentation

The prior period financial information in the company’s consolidated financial statements reflects the retrospective effects from the company’s January 1, 2018 adoption of Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers, and Accounting Standards Update (ASU) No. 2017-07, Compensation Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, and our fourth quarter 2018 change in accounting method related to the recognition of actuarial gains and losses for pension and other postretirement benefit (OPB) plans as discussed below.

Accounting Estimates

The company’s consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP” or “FAS”). The preparation thereof requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingencies at the date of the financial statements, as well as the reported amounts of sales and expenses during the reporting period. Estimates have been prepared using the most current and best available information; however, actual results could differ materially from those estimates.

Revenue Recognition

The majority of our sales are derived from long-term contracts with the U.S. government for the production of goods, the provision of services, or a combination of both. The company classifies sales as product or service based on the predominant attributes of each contract.

Under Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers, the company recognizes revenue for each separately identifiable performance obligation in a contract representing a promise to transfer a distinct good or service to a customer. In most cases, goods and services provided under the company’s contracts are accounted for as single performance obligations due to the complex and integrated nature of our products and services. These contracts generally require significant integration of a group of goods and/or services to deliver a combined output. In some contracts, the company provides multiple distinct goods or services to a customer, most commonly when a contract covers multiple phases of the product lifecycle (development, production, maintenance and/or support). In those cases, the company accounts for the distinct contract deliverables as separate performance obligations and allocates the transaction price to each performance obligation based on its relative standalone selling price, which is generally estimated using the cost plus a reasonable margin approach of ASC Topic 606. Warranties are provided on certain contracts, but do not typically provide for services beyond standard assurances and are therefore not within the scope of ASC Topic 606. Likewise, our accounting for costs to obtain or fulfill a contract was not significantly impacted by the adoption of ASC Topic 606 as these costs are not material.

A contract modification exists when the parties to a contract approve a change in the scope or price of a contract. Contracts are often modified for changes in contract specifications or requirements. Most of the company’s contract modifications are for goods or services that are not distinct in the context of the contract and are therefore accounted for as part of the original performance obligation through a cumulative estimate-at-completion (EAC) adjustment.

The company recognizes revenue as control is transferred to the customer, either over time or at a point in time. In general, our U.S. government contracts contain termination for convenience and/or other clauses that generally entitle the customer to goods produced and/or in-process. Similarly, our non-U.S. government contracts generally contain contractual termination clauses or entitle the company to payment for work performed to date for goods and services that do not have an alternative use. As control is effectively transferred while we perform on our contracts and we are typically entitled to cost plus a reasonable margin for work in process if the contract is terminated for convenience, we generally recognize revenue over time using the cost-to-cost method (cost incurred relative to total cost estimated at completion) as the company believes this represents the most appropriate measurement towards satisfaction of its performance obligations. Revenue for contracts in which the control of goods produced does not transfer until delivery to the customer is recognized at a point in time (i.e., typically upon delivery).

Contract Estimates

Use of the cost-to-cost method requires us to make reasonably dependable estimates regarding the revenue and cost associated with the design, manufacture and delivery of our products and services. The company estimates profit on these contracts as the difference between total estimated sales and total estimated cost at completion and recognizes that profit as costs are incurred. Significant judgment is used to estimate total revenue and cost at completion.

Contract sales may include estimates of variable consideration, including cost or performance incentives (such as award and incentive fees), contract claims and requests for equitable adjustment (REAs). Variable consideration is included in total estimated sales to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. We estimate variable consideration as the most likely amount to which we expect to be entitled.

We recognize changes in estimated contract sales or costs and the resulting changes in contract profit on a cumulative basis. Cumulative EAC adjustments represent the cumulative effect of the changes on current and prior periods; sales and operating margins in future periods are recognized as if the revised estimates had been used since contract inception. If it is determined that a loss is expected to result on an individual performance obligation, the entire amount of the estimable future loss, including an allocation of general and administrative (G&A) costs, is charged against income in the period the loss is identified. Each loss provision is first offset against costs included in Unbilled accounts receivable or Inventoried costs; remaining amounts are reflected in Other current liabilities.

Significant EAC adjustments on a single contract could have a material effect on the company’s consolidated financial statements. When such adjustments occur, we generally disclose the nature, underlying conditions and financial impact of the adjustments. During the second quarter of 2018, the company recognized $69 million of favorable EAC adjustments on multiple restricted programs at Aerospace Systems. During the third quarter of 2017, the company recorded a $56 million favorable EAC adjustment on a restricted program at Aerospace Systems.

The following table presents the effect of aggregate net EAC adjustments:



	Year Ended December 31
$ in millions, except per share data	2018		2017		2016
Operating income	$	577	$	360	$	443
Net earnings⁽¹⁾	456		234		288
Diluted earnings per share⁽¹⁾	2.61		1.33		1.60


⁽¹⁾	Based on statutory tax rates in effect for each year presented.

Revenue recognized from performance obligations satisfied in previous reporting periods was $631 million, $374 million and $463 million for the years ended December 31, 2018, 2017 and 2016, respectively.

Backlog

Backlog represents the future sales we expect to recognize on firm orders received by the company and is equivalent to the company’s remaining performance obligations at the end of each period. It comprises both funded backlog (firm orders for which funding is authorized and appropriated) and unfunded backlog. Unexercised contract options and indefinite delivery indefinite quantity (IDIQ) contracts are not included in backlog until the time an option or IDIQ task order is exercised or awarded.

Company backlog as of December 31, 2018 was $53.5 billion. We expect to recognize approximately 50 percent and 75 percent of our December 31, 2018 backlog as revenue over the next 12 and 24 months, respectively, with the remainder to be recognized thereafter.

Contract Assets and Liabilities

For each of the company’s contracts, the timing of revenue recognition, customer billings, and cash collections results in a net contract asset or liability at the end of each reporting period. Fixed-price contracts are typically billed to the customer either using progress payments, whereby amounts are billed monthly as costs are incurred or work is completed, or performance based payments, which are based upon the achievement of specific, measurable events or accomplishments defined and valued at contract inception. Cost-type contracts are typically billed to the customer on a monthly or semi-monthly basis.

Contract assets consist of unbilled receivables, primarily related to long-term contracts where revenue recognized under the cost-to-cost method exceeds amounts billed to customers. Unbilled receivables are classified as current assets and, in accordance with industry practice, include amounts that may be billed and collected beyond one year due to the long-cycle nature of many of our contracts. Accumulated contract costs in unbilled receivables include costs such as direct production costs, factory and engineering overhead, production tooling costs, and allowable G&A. Unbilled receivables also include certain estimates of variable consideration described above. These contract assets are not considered a significant financing component of the company’s contracts as the payment terms are intended to protect the customer in the event the company does not perform on its obligations under the contract.

Contract liabilities include advance payments and billings in excess of revenue recognized. Certain customers make advance payments prior to the company’s satisfaction of its obligations on the contract. These amounts are recorded as contract liabilities until such obligations are satisfied, either over time as costs are incurred or at a point in time when deliveries are made. Contract liabilities are not a significant financing component as they are generally utilized to pay for contract costs within a one-year period or are used to ensure the customer meets contractual requirements.

Net contract assets (liabilities) are as follows:



$ in millions	December 31, 2018			December 31, 2017			$ Change			% Change
Unbilled receivables, net	$	5,026		$	3,465		$	1,561		45	%
Advance payments and amounts in excess of costs incurred	(1,917		)	(1,761		)	(156		)	9	%
Net contract assets (liabilities)	$	3,109		$	1,704		$	1,405		82	%

The change in the balances of the company’s contract assets and liabilities primarily results from timing differences between revenue recognition and customer billings and/or payments. The increase in net contract assets during the year ended December 31, 2018 is principally due to the addition of $1.0 billion of net contract assets from Innovation Systems and a reduction of amounts in excess of costs incurred at Mission Systems.

The amount of revenue recognized for the years ended December 31, 2018, 2017 and 2016 that was included in the contract liability balance at the beginning of each year was $1.3 billion, $1.2 billion and $1.3 billion, respectively.

Disaggregation of Revenue

See Note 15 for information regarding the company’s sales by customer type, contract type and geographic region for each of our segments. We believe those categories best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors.

General and Administrative Expenses

In accordance with the regulations that govern cost accounting requirements for government contracts, most general management and corporate expenses incurred at the segment and corporate locations are considered allowable and allocable costs. Allowable and allocable G&A costs, including independent research and development (IR&D) and bid and proposal (B&P) costs, are allocated on a systematic basis to contracts in progress and are included as a component of total estimated contract costs.

Research and Development

Company-sponsored research and development activities primarily include efforts related to government programs. Company-sponsored IR&D expenses totaled $764 million, $639 million and $705 million in 2018, 2017 and 2016, respectively, which represented 2.5 percent, 2.5 percent and 2.9 percent of total sales, respectively. Customer-funded research and development activities are charged directly to the related contracts.

Income Taxes

Provisions for federal and foreign income taxes are calculated on reported earnings before income taxes based on current tax law and include the cumulative effect of any changes in tax rates from those used previously in determining deferred tax assets and liabilities. Such provisions differ from the amounts currently payable because certain items of income and expense are recognized in different periods for financial reporting purposes than for income tax purposes. The company recognizes federal and foreign interest accrued related to unrecognized tax benefits in income tax expense. Federal tax penalties are recognized as a component of income tax expense.

In accordance with the regulations that govern cost accounting requirements for government contracts, current state and local income and franchise taxes are generally considered allowable and allocable costs and, consistent with industry practice, are recorded in operating costs and expenses. The company recognizes changes in deferred state taxes and unrecognized state tax benefits in unallocated corporate expenses.

Uncertain tax positions reflect the company’s expected treatment of tax positions taken in a filed tax return, or planned to be taken in a future tax return or claim, which have not been reflected in measuring income tax expense for financial reporting purposes. Until these positions are sustained by the taxing authorities or the statute of limitations concerning such issues lapses, the company does not generally recognize the tax benefits resulting from such positions and reports the tax effects as a liability for uncertain tax positions in its consolidated statements of financial position.

Cash and Cash Equivalents

Cash and cash equivalents are comprised of cash in banks and highly liquid instruments with original maturities of three months or less, primarily consisting of bank time deposits and investments in institutional money market funds. Cash in bank accounts often exceeds federally insured limits.

Fair Value of Financial Instruments

The company measures the fair value of its financial instruments using observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect internal market assumptions.

These two types of inputs create the following fair value hierarchy:

Level 1 - Quoted prices for identical instruments in active markets.

Level 2 - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable.

Level 3 - Significant inputs to the valuation model are unobservable.

Marketable securities accounted for as trading are recorded at fair value on a recurring basis. Changes in unrealized gains and losses on trading securities are included in Other, net in the consolidated statements of earnings and comprehensive income. Investments in held-to-maturity instruments with original maturities greater than three months are recorded at amortized cost.

Derivative financial instruments are recognized as assets or liabilities in the financial statements and measured at fair value on a recurring basis. Changes in the fair value of derivative financial instruments that are designated as fair value hedges are recorded in net earnings, while the changes in the fair value of derivative financial instruments that are designated as cash flow hedges are recorded as a component of other comprehensive income until settlement. For derivative financial instruments not designated as hedging instruments, gains or losses resulting from changes in the fair value are reported in Other, net in the consolidated statements of earnings and comprehensive income.

The company may use derivative financial instruments to manage its exposure to interest rate risk for its long-term fixed-rate debt portfolio, foreign currency exchange risk related to receipts from customers and payments to suppliers denominated in foreign currencies and commodity price risk on purchases of inventory such as copper and zinc. The company does not use derivative financial instruments for trading or speculative purposes, nor does it use leveraged financial instruments. Credit risk related to derivative financial instruments is considered minimal and is managed through the use of multiple counterparties with high credit standards and periodic settlements of positions, as well as by entering into master netting agreements with most of our counterparties.

Inventoried Costs

Inventoried costs generally comprise costs associated with unsatisfied performance obligations on contracts accounted for using point in time revenue recognition, costs incurred in excess of existing contract requirements or funding that are probable of recovery and other accrued contract costs that are expected to be recoverable when allocated to specific contracts. Product inventory primarily consists of raw materials and is stated at the lower of cost or net realizable value, generally using the average method.

Accumulated contract costs in inventoried costs include costs such as direct production costs, factory and engineering overhead, production tooling costs, and allowable G&A. Inventoried costs are classified as current assets and, in accordance with industry practice, include amounts related to contracts having production cycles longer than one year.

Cash Surrender Value of Life Insurance Policies

The company maintains whole life insurance policies on a group of executives, which are recorded at their cash surrender value as determined by the insurance carrier. The company also has split-dollar life insurance policies on former officers and executives from acquired businesses, which are recorded at the lesser of their cash surrender value or premiums paid. These policies are utilized as a partial funding source for deferred compensation and other non-qualified employee retirement plans. As of December 31, 2018 and 2017, the carrying values associated with these policies were $316 million and $340 million, respectively, and are recorded in Other non-current assets in the consolidated statements of financial position.

Property, Plant and Equipment

Property, plant and equipment are depreciated over the estimated useful lives of individual assets. Most assets are depreciated using declining-balance methods, with the remainder using the straight-line method. Depreciation expense is generally recorded in the same segment where the related assets are held. However, the additional depreciation expense related to the step-up in fair value of property, plant and equipment acquired through business combinations is recorded in unallocated corporate expense within operating income as such depreciation is not considered part of management’s evaluation of segment operating performance. Major classes of property, plant and equipment and their useful lives are as follows:



		December 31
Useful life in years, $ in millions	Useful Life	2018			2017
Land and land improvements	Up to 40⁽¹⁾	$	636		$	420
Buildings and improvements	Up to 40	2,139			1,834
Machinery and other equipment	Up to 20	6,618			5,105
Capitalized software costs	3-5	603			537
Leasehold improvements	Length of Lease⁽²⁾	1,745			1,395
Property, plant and equipment, at cost		11,741			9,291
Accumulated depreciation		(5,369		)	(5,066		)
Property, plant and equipment, net		$	6,372		$	4,225


⁽¹⁾	Land is not a depreciable asset.


⁽²⁾	Leasehold improvements are depreciated over the shorter of the useful life of the asset or the length of the lease.

Goodwill and Other Purchased Intangible Assets

The company tests goodwill for impairment at least annually as of December 31, or when an indicator of potential impairment exists. When performing the goodwill impairment test, the company uses a discounted cash flow approach corroborated by comparative market multiples, where appropriate, to determine the fair value of its reporting units.

Goodwill and other purchased intangible asset balances are included in the identifiable assets of their assigned business segment. Beginning in 2018, the company includes the amortization of other purchased intangible assets in unallocated corporate expense within operating income as such amortization is no longer considered part of management’s evaluation of segment operating performance. The company’s customer-related intangible assets are generally amortized over their respective useful lives based on the pattern in which the future economic benefits of the intangible assets are expected to be consumed. Other intangible assets are generally amortized on a straight-line basis over their estimated useful lives.

Leases

The company uses its incremental borrowing rate in the assessment of lease classification as capital or operating and defines the initial lease term to include renewal options determined to be reasonably assured. The majority of our leases are operating leases.

Many of the company’s real property lease agreements contain incentives for tenant improvements, rent holidays, or rent escalation clauses. For tenant improvement incentives, the company records a deferred rent liability and amortizes the deferred rent over the term of the lease as a reduction to rent expense. For rent holidays and rent escalation clauses during the lease term, the company records rental expense on a straight-line basis over the term of the lease. For purposes of recognizing lease incentives, the company uses the date of initial possession as the commencement date, which is generally when the company is given the right of access to the space and begins to make improvements in preparation for intended use.

Litigation, Commitments and Contingencies

We accrue for litigation, commitments and contingencies when management, after considering the facts and circumstances of each matter as then known to management, has determined it is probable a liability will be found to have been incurred and the amount of the loss can be reasonably estimated. When only a range of amounts is reasonably estimable and no amount within the range is more likely than another, the low end of the range is recorded. Legal fees are expensed as incurred. Due to the inherent uncertainties surrounding gain contingencies, we generally do not recognize potential gains until realized.

Environmental Costs

We accrue for environmental liabilities when management determines that, based on the facts and circumstances known to the company, it is probable the company will incur costs to address environmental impacts and the costs are reasonably estimable. When only a range of amounts is reasonably estimable and no amount within the range is more probable than another, we record the low end of the range. The company typically projects environmental costs for up to 30 years, records environmental liabilities on an undiscounted basis, and excludes asset retirement obligations and certain legal costs. At sites involving multiple parties, we accrue environmental liabilities based upon our expected share of liability, taking into account the financial viability of other liable parties. As a portion of environmental remediation liabilities are expected to be recoverable through overhead charges on government contracts, such amounts are deferred in prepaid expenses and other current assets (current portion) and other non-current assets until charged to contracts. The portion of environmental costs not expected to be recoverable is expensed.

Retirement Benefits

The company sponsors various defined benefit pension plans and defined contribution retirement plans covering substantially all of its employees. In most cases, our defined contribution plans provide for a company match of employee contributions. The company also provides postretirement benefits other than pensions to eligible retirees and qualifying dependents, consisting principally of health care and life insurance benefits.

The liabilities, unamortized prior service credits and annual income or expense of the company’s defined benefit pension and OPB plans are determined using methodologies that involve several actuarial assumptions.

Because U.S. government regulations require that the costs of pension and OPB plans be charged to our contracts in accordance with the Federal Acquisition Regulation (FAR) and the related U.S. Government Cost Accounting Standards (CAS) that govern such plans, we calculate retiree benefit plan costs under both CAS and FAS methods. While both FAS and CAS recognize a normal service cost component in measuring periodic pension cost, there are differences in the way the components of annual pension costs are calculated under each method. Measuring plan obligations under FAS and CAS includes different assumptions and models, such as in estimating returns on plan assets, calculating interest expense and the periods over which gains/losses related to pension assets and actuarial changes are recognized. As a result, annual retiree benefit plan expense amounts for FAS are different from the amounts for CAS in any given reporting period even though the ultimate cost of providing benefits over the life of the plans is the same under either method. CAS retiree benefit plan costs are charged to contracts and are included in segment operating income, and the difference between the service cost component of FAS expense and total CAS expense is recorded in operating income at the consolidated company level. Not all net periodic pension expense is recognized in net earnings in the year incurred because it is allocated as production costs and a portion remains in inventory at the end of a reporting period.

Change in Accounting Method

During the fourth quarter of 2018, we changed our GAAP accounting method related to the recognition of actuarial gains and losses for the company’s pension and OPB plans (the “Accounting change”). Prior to the Accounting change, actuarial gains and losses were recognized as a component of Accumulated other comprehensive (loss) income upon annual remeasurement and were amortized into earnings in future periods on a plan-by-plan basis when they exceeded the accounting corridor, a defined range within which amortization of net gains and losses is not required.

Under the new method, actuarial gains and losses are immediately recognized in net periodic benefit cost through Mark-to-market pension and OPB (“MTM”) (expense) benefit upon annual remeasurement in the fourth quarter, or on an interim basis as triggering events warrant remeasurement. Prior service credits will continue to be recognized as a component of Accumulated other comprehensive (loss) income and amortized into earnings in future periods. While the historical accounting principle was acceptable, we believe the Accounting change is preferable as it better aligns with fair value principles by recognizing the effects of economic and interest rate changes in our pension and OPB assets and liabilities in the year in which the gains and losses are incurred rather than amortizing them over time. The Accounting change has been applied retrospectively to all prior years presented. As of January 1, 2016, the cumulative effect of this change resulted in a $5.5 billion decrease to retained earnings and a corresponding $5.5 billion increase to accumulated other comprehensive (loss) income, both net of tax of $3.5 billion.

See Notes 13, 16, 17 and 18 for further information regarding the impact of the Accounting change on our current and prior period consolidated financial statements.

Stock Compensation

The company’s stock compensation plans are classified as equity plans and compensation expense is generally recognized over the vesting period of stock awards (typically three years), net of estimated forfeitures. The company issues stock awards in the form of restricted performance stock rights and restricted stock rights. The fair value of stock awards is determined based on the closing market price of the company’s common stock on the grant date. At each reporting date, the number of shares used to calculate compensation expense and diluted earnings per share is adjusted to reflect the number ultimately expected to vest.

Accumulated Other Comprehensive (Loss) Income

The components of accumulated other comprehensive (loss) income are as follows:



	December 31
$ in millions	2018			2017
Unamortized prior service credit, net of tax expense of $32 for 2018 and $76 for 2017	$	98		$	133
Cumulative translation adjustment	(144		)	(136		)
Other, net	(6		)	4
Total accumulated other comprehensive (loss) income	$	(52	)	$	1

Unamortized prior service credit as of December 31, 2018 reflects a reclassification from accumulated other comprehensive (loss) income to retained earnings of $25 million of stranded tax effects resulting from the 2017 Tax Act. This reclassification, which was calculated after consideration of the Accounting change, resulted from the company’s early adoption of ASU 2018-02 on January 1, 2018. See “Accounting Standards Updates” below for more information.

Reclassifications from accumulated other comprehensive (loss) income to net earnings related to the amortization of prior service credit were $60 million, $44 million and $62 million, net of taxes, for the years ended December 31, 2018, 2017 and 2016, respectively. The reclassifications are included in the computation of net periodic benefit cost. See Note 13 for further information.

Reclassifications from accumulated other comprehensive (loss) income to net earnings, relating to cumulative translation adjustments, marketable securities (prior to the January 1, 2018 adoption of ASU 2016-01) and cash flow hedges were not material for the years ended December 31, 2018, 2017 and 2016.

Related Party Transactions

For all periods presented, the company had no material related party transactions.

Accounting Standards Updates

On February 14, 2018, the Financial Accounting Standards Board (FASB) issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. ASU 2018-02 allows companies to reclassify stranded tax effects resulting from the 2017 Tax Act from accumulated other comprehensive (loss) income to retained earnings. As described above, the company elected to early adopt ASU 2018-02 on January 1, 2018, which resulted in a reclassification of $25 million of stranded tax effects, related to our unamortized prior service credits, from accumulated other comprehensive (loss) income to retained earnings. Adoption of ASU 2018-02 did not have a material impact on the company’s results of operations and/or cash flows.

On March 10, 2017, the FASB issued ASU No. 2017-07, Compensation Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. ASU 2017-07 requires employers that sponsor defined benefit pension and/or OPB plans to report the service cost component of net benefit cost in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. Employers are required to present the other components of net benefit costs in the income statement separately from the service cost component and outside a subtotal of income from operations. Additionally, only the service cost component of net periodic pension cost is eligible for asset capitalization. We adopted ASU 2017-07 on January 1, 2018 using the retrospective method. Adoption of ASU 2017-07 did not have a material impact on our consolidated statements of financial position and/or cash flows. See Note 18 for further information regarding the impact of adopting ASU 2017-17 on our consolidated statements of earnings and comprehensive income.

On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). ASU 2016-02 supersedes existing lease guidance, including ASC 840 - Leases. Among other things, ASU 2016-02 requires recognition of a right-of-use asset and liability for future lease payments for contracts that meet the definition of a lease and requires disclosure of certain information about leasing arrangements. ASU 2016-02 will be effective January 1, 2019, although early adoption is permitted. On July 30, 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements, which, among other things, allows companies to elect an optional transition method to apply the new lease standard through a cumulative-effect adjustment in the period of adoption. We adopted the standard on January 1, 2019 using the optional transition method. The company has made substantial progress in executing our implementation plan. We have revised our controls and processes to address the lease standard and have completed the implementation and data input for our lease accounting software tool. We are electing the package of practical expedients, which, among other things, allows us to carry forward our prior lease classifications under ASC 840. However, we are not electing to adopt the hindsight practical expedient and are therefore maintaining the lease terms we previously determined under ASC 840. Adoption of the standard is expected to have an impact of approximately $1.4 billion on our consolidated statement of financial position for the addition of lease assets and liabilities related to operating leases. ASU 2016-02 also requires expanded disclosure regarding the amounts, timing and uncertainties of cash flows related to a company’s lease portfolio. We are evaluating these disclosure requirements and are incorporating the collection of relevant data into our processes in preparation for disclosure in 2019. We do not expect ASU 2016-02 to have a material impact on our annual results of operations and/or cash flows.

On January 5, 2016, the FASB issued ASU No. 2016-01, Financial Instruments (Topic 825): Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 requires equity investments that are not accounted for under the equity method of accounting or that do not result in consolidation of the investee to be measured at fair value with changes recognized in net earnings. ASU 2016-01 also eliminates the available-for-sale classification for equity investments that recognized changes in fair value as a component of other comprehensive income. We adopted ASU 2016-01 on January 1, 2018 using the modified retrospective method, which resulted in a $4 million (net of tax) cumulative-effect adjustment from accumulated other comprehensive (loss) income to retained earnings. Adoption of ASU 2016-01 did not have a material impact on our results of operations and/or cash flows.

On May 28, 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). Topic 606 supersedes previous revenue recognition guidance, including ASC 605-35, Revenue Recognition - Construction-Type and Production-Type Contracts, and outlines a single set of comprehensive principles for recognizing revenue under U.S. GAAP. Among other things, it requires companies to identify contractual performance obligations and determine whether revenue should be recognized at a point in time or over time. The primary impact of the adoption of ASC Topic 606 was that, in most cases, the accounting for those contracts where we previously recognized revenue as units were delivered changed under ASC Topic 606 such that we now recognize revenue as over time as costs are incurred. In addition, for certain of our contracts, there is a change in the number of performance obligations under ASC Topic 606, which has altered the timing of revenue and margin recognition.

We adopted ASC Topic 606 on January 1, 2018 using the full retrospective method. We applied the transition practical expedient related to remaining performance obligations for reporting periods presented before the date of initial application. No other practical expedients were applied. The cumulative effect of adopting ASC Topic 606 was a $148 million increase to retained earnings at January 1, 2016. See Note 18 for further information regarding the impact of adopting ASC Topic 606 on our consolidated financial statements.

Other accounting standards updates adopted and/or issued, but not effective until after December 31, 2018, are not expected to have a material effect on the company’s consolidated financial position, annual results of operations and/or cash flows.

Acquisition of Orbital ATK

12 Months Ended

Dec. 31, 2018

Business Combination [Abstract]

Business Combination Disclosure [Text Block]

2. ACQUISITION OF ORBITAL ATK

On June 6, 2018, the company completed its previously announced acquisition of Orbital ATK, by acquiring all of the outstanding shares of Orbital ATK for a purchase price of $7.7 billion in cash. On the Merger date, Orbital ATK became a wholly-owned subsidiary of the company and its name was changed to Northrop Grumman Innovation Systems, Inc. We established Innovation Systems as a new, fourth business sector, whose main products include launch vehicles and related propulsion systems; missile products and defense electronics; precision weapons, armament systems and ammunition; satellites and associated space components and services; and advanced aerospace structures. The acquisition was financed with proceeds from the company’s debt financing completed in October 2017 and cash on hand. We believe this acquisition will enable us to broaden our capabilities and offerings, provide additional innovative solutions to meet our customers’ emerging requirements, create value for shareholders and provide expanded opportunities for our combined employees.

The operating results of Innovation Systems subsequent to the Merger date are included in the company's consolidated results of operations. Innovation Systems recognized sales of $3.3 billion, operating income of $343 million and net earnings of $273 million for the period from the Merger date to December 31, 2018.

The company recognized $29 million of acquisition-related costs that were expensed as incurred during the year ended December 31, 2018. These costs are included in Product and Service cost in the consolidated statements of earnings and comprehensive income.

Preliminary Purchase Price Allocation

The acquisition was accounted for as a purchase business combination. As such, the company recorded the assets acquired and liabilities assumed at fair value, with the excess of the purchase price over the fair value of assets acquired and liabilities assumed recorded as goodwill. Determining the fair value of assets acquired and liabilities assumed requires significant judgment, including the amount and timing of expected future cash flows, long-term growth rates and discount rates. In some cases, the company used discounted cash flow analyses, which were based on our best estimate of future sales, earnings and cash flows after considering such factors as general market conditions, customer budgets, existing firm and future orders, changes in working capital, long term business plans and recent operating performance. Use of different estimates and judgments could yield materially different results.

During the second quarter of 2018, the company completed a preliminary analysis to determine the fair values of the assets acquired and liabilities assumed and the amounts recorded reflected management’s initial assessment of fair value as of the Merger date. Based on additional information obtained to date, the company refined its initial assessment of fair value and recognized the following significant adjustments to our preliminary purchase price allocation: Intangible assets increased $220 million, Other current liabilities increased $114 million, Pension and OPB plan liabilities increased $56 million and Goodwill decreased $73 million. These adjustments did not result in a material impact on the financial results of prior periods.

The company expects to finalize its purchase price allocation within one year of the Merger date. We are continuing to analyze and assess relevant information in the following areas to determine the fair value of assets acquired and liabilities assumed as of the Merger Date: income tax and certain legal and contract-related matters. The final fair value determination could result in material adjustments to the values presented in the preliminary purchase price allocation table below.

The Merger date fair value of the consideration transferred totaled $7.7 billion in cash, which was comprised of the following:



$ in millions, except per share amounts	Purchase price
Shares of Orbital ATK common stock outstanding as of the Merger date	57,562,152
Cash consideration per share of Orbital ATK common stock	$	134.50
Total purchase price	$	7,742

The following preliminary purchase price allocation table presents the company’s refined estimate of the fair values of assets acquired and liabilities assumed at the Merger date:



$ in millions	As of June 6, 2018
Cash and cash equivalents	$	85
Accounts receivable	596
Unbilled receivables	1,264
Inventoried costs	220
Other current assets	214
Property, plant and equipment	1,509
Goodwill	6,222
Intangible assets	1,525
Other non-current assets	151
Total assets acquired	11,786
Trade accounts payable	(397		)
Accrued employee compensation	(158		)
Advance payments and amounts in excess of costs incurred	(222		)
Below market contracts⁽¹⁾	(151		)
Other current liabilities	(412		)
Long-term debt	(1,687		)
Pension and OPB plan liabilities	(613		)
Deferred tax liabilities	(248		)
Other non-current liabilities	(156		)
Total liabilities assumed	(4,044		)
Total purchase price	$	7,742


⁽¹⁾	Included in Other current liabilities in the consolidated statements of financial position.

Below market contracts represent liabilities on certain acquired programs where the expected costs at completion exceed the expected sales under contract. We measured these liabilities based on the estimated price to transfer the obligations to a market participant at the Merger date plus a reasonable profit margin. These liabilities will be reduced as the company incurs costs to complete its performance obligations on the underlying programs. This reduction will be included in sales and is estimated as follows: $64 million in 2019, $45 million in 2020, and $2 million in 2021.

The following table presents a summary of purchased intangible assets and their related estimated useful lives:

The preliminary purchase price allocation resulted in the recognition of $6.2 billion of goodwill, a majority of which was allocated to the Innovation Systems sector (refer to Note 8). The goodwill recognized is attributable to expected revenue synergies generated by the integration of Aerospace Systems, Mission Systems and Technology Services products and technologies with those of legacy Orbital ATK, synergies resulting from the consolidation or elimination of certain costs, and intangible assets that do not qualify for separate recognition, such as the assembled workforce of Orbital ATK. None of the goodwill is expected to be deductible for tax purposes.

Unaudited Supplemental Pro Forma Information

The following table presents unaudited pro forma financial information prepared in accordance with Article 11 of Regulation S-X and computed as if Orbital ATK had been included in our results as of January 1, 2017:



	Year Ended December 31
$ in millions, except per share amounts	2018		2017
Sales	$	32,319	$	30,634
Net earnings	3,417		2,938
Diluted earnings per share	19.57		16.73

The unaudited supplemental pro forma financial data has been calculated after applying our accounting policies and adjusting the historical results of Orbital ATK with pro forma adjustments, net of tax, that assume the acquisition occurred on January 1, 2017. Significant pro forma adjustments include the following:


1.	The impact of the adoption of ASC Topic 606 on Orbital ATK’s historical sales of $21 million and cost of sales of $21 million, for the year ended December 31, 2017.


2.	The elimination of intercompany sales and costs of sales between the company and Orbital ATK of $80 million and $155 million for the years ended December 31, 2018 and 2017, respectively.


3.	The elimination of nonrecurring transaction costs incurred by the company and Orbital ATK in connection with the Merger of $71 million and $57 million for the years ended December 31, 2018 and 2017, respectively.


4.	The recognition of additional depreciation expense, net of removal of historical depreciation expense, of $8 million and $40 million for the years ended December 31, 2018 and 2017, respectively, related to the step-up in fair value of acquired property, plant and equipment.


5.	Additional interest expense related to the debt issued to finance the Merger, including amortization of the debt issuance costs associated with the newly issued debt, of $208 million for the year ended December 31, 2017. Interest expense and amortization of debt issuance costs have been included in the company's historical financial statements since the date of issuance (October 12, 2017).


6.	The recognition of additional amortization expense, net of removal of historical amortization expense, of $90 million and $290 million for the years ended December 31, 2018 and 2017, respectively, related to the fair value of acquired intangible assets.


7.	The elimination of Orbital ATK's historical amortization of net actuarial losses and prior service credits and impact of the revised pension and OPB net periodic benefit cost as determined under the company’s plan assumptions of $51 million and $110 million for the years ended December 31, 2018 and 2017, respectively.


8.	The income tax effect on the pro forma adjustments, which was calculated using the federal statutory tax rate in effect in each respective period, of $(5) million and $130 million for the years ended December 31, 2018 and 2017, respectively.

The unaudited pro forma financial information does not reflect the potential realization of revenue synergies or cost savings, nor does it reflect other costs relating to the integration of the two companies. This unaudited pro forma financial information should not be considered indicative of the results that would have actually occurred if the acquisition had been consummated on January 1, 2017, nor are they indicative of future results.

Earnings Per Share, Share Repurchases and Dividends on Common Stock

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Earnings Per Share, Share Repurchases and Dividends on Common Stock

3. EARNINGS PER SHARE, SHARE REPURCHASES AND DIVIDENDS ON COMMON STOCK

Basic Earnings Per Share

We calculate basic earnings per share by dividing net earnings by the weighted-average number of shares of common stock outstanding during each period.

Diluted Earnings Per Share

Diluted earnings per share include the dilutive effect of awards granted to employees under stock-based compensation plans. The dilutive effect of these securities totaled 0.9 million, 1.2 million and 1.6 million shares for the years ended December 31, 2018, 2017 and 2016, respectively.

Share Repurchases

On December 4, 2014, the company’s board of directors authorized a share repurchase program of up to $3.0 billion of the company’s common stock (the “2014 Repurchase Program”). Repurchases under the 2014 Repurchase Program commenced in March 2015 and were completed in March 2016.

On September 16, 2015, the company’s board of directors authorized a share repurchase program of up to $4.0 billion of the company’s common stock (the “2015 Repurchase Program”). Repurchases under the 2015 Repurchase Program commenced in March 2016.

On December 4, 2018, the company’s board of directors authorized a new share repurchase program of up to an additional $3.0 billion in share repurchases of the company’s common stock (the “2018 Repurchase Program”). By its terms, repurchases under the 2018 Repurchase Program will commence upon completion of the 2015 Repurchase Program and will expire when we have used all authorized funds for repurchases.

During the fourth quarter of 2018, the company entered into an accelerated share repurchase (ASR) agreement with Goldman Sachs & Co. LLC (Goldman Sachs) to repurchase $1.0 billion of the company’s common stock as part of the 2015 Repurchase Program. Under the agreement, we made a payment of $1.0 billion to Goldman Sachs and received an initial delivery of 3.0 million shares valued at $800 million that were immediately canceled by the company. The remaining balance of $200 million, included as a reduction to Retained earnings on the consolidated statement of financial position, settled on January 4, 2019 with a final delivery of 0.9 million shares from Goldman Sachs. The final average purchase price was $260.32 per share.

As of December 31, 2018, repurchases under the 2015 Repurchase Program totaled $2.7 billion; $1.3 billion remained under this share repurchase authorization. $200 million of this share repurchase authorization was used to settle the ASR on January 4, 2019. By its terms, the 2015 Repurchase Program is set to expire when we have used all authorized funds for repurchases.

Share repurchases take place from time to time, subject to market conditions and management’s discretion, in the open market or in privately negotiated transactions. The company retires its common stock upon repurchase and, in the periods presented, has not made any purchases of common stock other than in connection with these publicly announced repurchase programs.

The table below summarizes the company’s share repurchases to date under the authorizations described above:



Repurchase Program Authorization Date	Amount Authorized (in millions)		Total Shares Retired (in millions)	Average Price Per Share⁽¹⁾		Date Completed	Shares Repurchased (in millions)
							Shares Repurchased (in millions)
							Year Ended December 31
							2018	2017	2016
December 4, 2014	$	3,000	18.0	$	166.70	March 2016	—	—	1.4
September 16, 2015	$	4,000	11.3	$	241.66		3.8	1.6	5.9
December 4, 2018	$	3,000	—	$	—		—	—	—
							3.8	1.6	7.3


⁽¹⁾	Includes commissions paid.

Dividends on Common Stock

In May 2018, the company increased the quarterly common stock dividend 9 percent to $1.20 per share from the previous amount of $1.10 per share.

In January 2018, the company increased the quarterly common stock dividend 10 percent to $1.10 per share from the previous amount of $1.00 per share.

In May 2017, the company increased the quarterly common stock dividend 11 percent to $1.00 per share from the previous amount of $0.90 per share.

In May 2016, the company increased the quarterly common stock dividend 13 percent to $0.90 per share from the previous amount of $0.80 per share.

Accounts Receivable, Net

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts Receivable, Net

4. ACCOUNTS RECEIVABLE, NET

Accounts receivable, net represent amounts billed and due from customers. Substantially all accounts receivable at December 31, 2018 are expected to be collected in 2019. The company does not believe it has significant exposure to credit risk as accounts receivable are primarily due from the U.S. government either as the ultimate customer or in connection with foreign military sales.

Accounts receivable consisted of the following:



	December 31
$ in millions	2018			2017
Due from U.S. government ⁽¹⁾	$	1,164		$	825
Due from international and other customers	318			268
Accounts receivable, gross	1,482			1,093
Allowance for doubtful accounts	(34		)	(39		)
Accounts receivable, net	$	1,448		$	1,054


⁽¹⁾	Includes receivables due from the U.S. government associated with foreign military sales (FMS). For FMS, we contract with and are paid by the U.S. government.

- Definition

The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.

+ References + Details

Unbilled Receivables, Net

12 Months Ended

Dec. 31, 2018

Unbilled Receivables, Net [Abstract]

Loans, Notes, Trade and Other Receivables Disclosure [Text Block]

5. UNBILLED RECEIVABLES, NET

Unbilled receivables, net represent revenue recognized under the cost-to-cost method that exceeds amounts billed to customers. Substantially all unbilled receivables at December 31, 2018 are expected to be billed and collected in 2019. Progress and performance-based payments are reflected as an offset to the related unbilled receivable balances.

Unbilled receivables consisted of the following:



	December 31
$ in millions	2018			2017
Due from U.S. government ⁽¹⁾
Unbilled receivables	$	16,823		$	12,513
Progress and performance-based payments received	(12,539		)	(9,447		)
Total due from U.S. government	4,284			3,066
Due from international and other customers
Unbilled receivables	3,811			3,424
Progress and performance-based payments received	(3,030		)	(2,986		)
Total due from international and other customers	781			438
Unbilled receivables, net of progress and performance-based payments received	5,065			3,504
Allowance for doubtful accounts	(39		)	(39		)
Unbilled receivables, net	$	5,026		$	3,465


⁽¹⁾	Includes unbilled receivables due from the U.S. government associated with FMS sales. For FMS, we contract with and are paid by the U.S. government.

Inventoried Costs, Net

12 Months Ended

Dec. 31, 2018

Inventory Disclosure [Abstract]

Inventoried Costs, Net

6. INVENTORIED COSTS, NET

Inventoried costs are primarily from contracts where the U.S. government is the primary customer, therefore the company does not believe it has significant exposure to recoverability risk related to these amounts.

Inventoried costs, net consisted of the following:



	December 31
$ in millions	2018			2017
Production costs of contracts in process	$	402		$	312
G&A expenses	16			30
	418			342
Progress and performance-based payments received	(41		)	(41		)
	377			301
Product inventory and raw material	277			97
Inventoried costs, net	$	654		$	398

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

7. INCOME TAXES

In December 2017, the 2017 Tax Act was enacted. The 2017 Tax Act includes a number of changes to previous U.S. tax laws that impact the company, most notably a reduction of the U.S. corporate income tax rate from 35 percent to 21 percent for tax years beginning after December 31, 2017. The 2017 Tax Act also provides for a one-time transition tax on certain foreign earnings and the acceleration of depreciation for certain assets placed into service after September 27, 2017 as well as prospective changes which began in 2018, including repeal of the domestic manufacturing deduction, capitalization of research and development expenditures, additional limitations on executive compensation and limitations on the deductibility of interest.

The company recognized the income tax effects of the 2017 Tax Act in its financial statements in accordance with Staff Accounting Bulletin (SAB) No. 118, which provides SEC staff guidance for the application of ASC Topic 740, Income Taxes. The company finalized its accounting for the income tax effects of the 2017 Tax Act in the third quarter of 2018.

The following tables present the impact of the 2017 Tax Act relating to SAB 118 amounts as an increase (decrease) reflected in the noted line items in the Consolidated Statements of Earnings and Comprehensive Income and Consolidated Statements of Financial Position:



	Year Ended December 31
$ in millions	2018		2017		2018		2017
	Income Tax Expense				Income Tax Rate
Reduction of U.S. Corporate Income Tax Rate	$	—	$	265	—	%	6.3	%
Transition Tax on Foreign Earnings	5		13		0.1		0.3
Acceleration of Depreciation	—		5		—		0.1
Other	—		2		—		0.1
Total	$	5	$	285	0.1	%	6.8	%



	Year Ended December 31
$ in millions	2018			2017			2018		2017
	Deferred Tax Assets						Other Current Liabilities
Reduction of U.S. Corporate Income Tax Rate	$	—		$	(265	)	$	—	$	—
Transition Tax on Foreign Earnings	(5		)	(13		)	—		—
Acceleration of Depreciation	17			(80		)	17		(75		)
Other	—			—			—		2
Total	$	12		$	(358	)	$	17	$	(73	)

Income Tax Expense

Federal and foreign income tax expense consisted of the following:



	Year Ended December 31
$ in millions	2018		2017			2016
Federal income tax expense:
Current	$	292	$	449		$	661
Deferred	213		907			(36		)
Total federal income tax expense	505		1,356			625
Foreign income tax expense:
Current	7		8			14
Deferred	1		(4		)	(1		)
Total foreign income tax expense	8		4			13
Total federal and foreign income tax expense	$	513	$	1,360		$	638

Earnings from foreign operations before income taxes are not material for all periods presented.

Income tax expense differs from the amount computed by multiplying earnings before income taxes by the statutory federal income tax rate due to the following:



	Year Ended December 31
$ in millions	2018					2017					2016
Income tax expense at statutory rate	$	786		21.0	%	$	1,480		35.0	%	$	938		35.0	%
Stock compensation - excess tax benefits	(27		)	(0.7	)	(48		)	(1.1	)	(85		)	(3.2	)
Research credit	(186		)	(5.0	)	(130		)	(3.1	)	(61		)	(2.2	)
Manufacturing deduction	—			—		(97		)	(2.3	)	(58		)	(2.2	)
Settlements with taxing authorities	—			—		(42		)	(1.0	)	(40		)	(1.5	)
Repatriation of non-U.S. earnings	—			—		—			—		(33		)	(1.2	)
Impacts related to the 2017 Tax Act	(84		)	(2.2	)	285			6.8		—			—
MTM benefit tax rate differential⁽¹⁾	—			—		(72		)	(1.7	)	—			—
Other, net	24			0.6		(16		)	(0.4	)	(23		)	(0.9	)
Total federal and foreign income taxes	$	513		13.7	%	$	1,360		32.2	%	$	638		23.8	%


⁽¹⁾	Impact of applying the 2017 Tax Act enacted statutory tax rate of 21% versus 35%.

2018 – The effective tax rate for 2018 was 13.7 percent, as compared with 32.2 percent in 2017, principally due to the reduction of the U.S. corporate income tax rate from 35 percent to 21 percent as a result of the 2017 Tax Act and a $56 million increase in research credits. In addition, the company’s effective tax rate for 2017 includes $285 million of tax expense recorded in connection with the 2017 Tax Act, largely due to the write-down of net deferred tax assets, offset by $97 million of tax benefits associated with manufacturing deductions and a $72 million tax benefit from the impact of applying the 2017 Tax Act enacted statutory tax rate of 21% versus 35% to the 2017 MTM benefit.

2017 – The effective tax rate for 2017 was 32.2 percent, as compared with 23.8 percent in 2016. The higher rate is principally due to $285 million of tax expense recorded in connection with the 2017 Tax Act, largely due to the write-down of net deferred tax assets, partially offset by a $69 million increase in research credits and a $39 million benefit recognized for additional manufacturing deductions principally related to prior years. The effective tax rates for the years ended December 31, 2017 and 2016 each include separate approximately $40 million benefits recognized in connection with the resolution of Internal Revenue Service (IRS) examinations of the company’s prior year tax returns.

Income tax payments, net of refunds received, were $270 million, $517 million and $691 million for the years ended December 31, 2018, 2017 and 2016, respectively.

Uncertain Tax Positions

In connection with the Merger, the company has initially recognized an increase in unrecognized tax benefits of approximately $160 million for matters associated with legacy Orbital ATK, principally related to federal and state research credits. In addition, during 2018, we increased our unrecognized tax benefits related to our methods of accounting associated with the 2017 Tax Act by approximately $100 million and it is reasonably possible that within the next twelve months those unrecognized tax benefits may increase by up to an additional $70 million.

We file income tax returns in the U.S. federal jurisdiction and in various state and foreign jurisdictions. The Northrop Grumman 2014-2015 federal tax returns and refund claims related to its 2007-2016 federal tax returns are currently under IRS examination. In addition, legacy Orbital ATK federal tax returns for the year ended March 31, 2015 and nine-month transition period ended December 31, 2015 are currently under IRS examination.

Tax returns for open tax years related to state and foreign jurisdictions remain subject to examination, but the amounts currently subject to examination are not material.

The change in unrecognized tax benefits during 2018, 2017 and 2016, excluding interest, is as follows:



	December 31
$ in millions	2018			2017			2016
Unrecognized tax benefits at beginning of the year	$	283		$	135		$	223
Additions based on tax positions related to the current year	293			102			35
Additions for tax positions of prior years	207			110			2
Reductions for tax positions of prior years	(23		)	(44		)	(40		)
Settlements with taxing authorities	(7		)	(20		)	(84		)
Other, net	(5		)	—			(1		)
Net change in unrecognized tax benefits	465			148			(88		)
Unrecognized tax benefits at end of the year	$	748		$	283		$	135

These liabilities, along with $24 million of accrued interest and penalties, are included in other current and non-current liabilities in the consolidated statements of financial position. If the income tax benefits from these tax positions are ultimately realized, $430 million of federal and foreign tax benefits would reduce the company’s effective tax rate.

Net interest expense within the company’s federal, foreign and state income tax provisions was not material for all years presented.

Deferred Income Taxes

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and tax purposes. Net deferred tax assets and liabilities are classified as non-current in the consolidated statements of financial position.

The tax effects of significant temporary differences and carryforwards that gave rise to year-end deferred federal, state and foreign tax balances, as presented in the consolidated statements of financial position, are as follows:



	December 31
$ in millions	2018			2017
Deferred Tax Assets
Retiree benefits	$	1,541		$	1,477
Accrued employee compensation	308			263
Provisions for accrued liabilities	139			193
Inventory	650			447
Stock-based compensation	42			46
Tax credits	174			9
Other	59			30
Gross deferred tax assets	2,913			2,465
Less valuation allowance	(142		)	(26		)
Net deferred tax assets	2,771			2,439
Deferred Tax Liabilities
Goodwill	511			508
Purchased intangibles	346			9
Property, plant and equipment, net	518			256
Contract accounting differences	1,381			1,182
Other	29			37
Deferred tax liabilities	2,785			1,992
Total net deferred tax (liabilities) assets	$	(14	)	$	447

Realization of deferred tax assets is primarily dependent on generating sufficient taxable income in future periods. The company believes it is more-likely-than-not our net deferred tax assets will be realized.

At December 31, 2018, the company has available tax credits and unused net operating losses of $255 million and $330 million, respectively, that may be applied against future taxable income. The majority of tax credits and net operating losses expire in 2019 through 2039, however, some may be carried forward indefinitely. Due to the uncertainty of the realization of the tax credits and net operating losses, the company has recorded valuation allowances of $110 million and $27 million as of December 31, 2018, respectively.

Undistributed Foreign Earnings

As of December 31, 2018, the company has accumulated undistributed earnings generated by our foreign subsidiaries and most have been taxed in the U.S. as a result of the 2017 Tax Act. The 2017 Tax Act allows for a dividend received deduction for repatriation of earnings. We intend to indefinitely reinvest these earnings, as well as future earnings from our foreign subsidiaries, to fund our international operations and foreign credit facility. In addition, we expect future U.S. cash generation will be sufficient to meet future U.S. cash needs.

Goodwill and Other Purchased Intangible Assets

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

8. GOODWILL AND OTHER PURCHASED INTANGIBLE ASSETS

Goodwill

As discussed in Note 2, Innovation Systems was established as a new, fourth business sector of the company. The Merger resulted in the recognition of $6.2 billion of goodwill, a majority of which was allocated to the Innovation Systems sector. A portion of this goodwill was allocated to the company’s other sectors based on expected revenue synergies generated by the integration of their products and technologies with those of Innovation Systems. The amount of goodwill recognized is subject to change, pending the final determination of the fair value of assets acquired and liabilities assumed in connection with the Merger (see Note 2).

Changes in the carrying amounts of goodwill for the years ended December 31, 2017 and 2018, were as follows:



$ in millions	Aerospace Systems		Innovation Systems		Mission Systems			Technology Services			Total
Balance as of December 31, 2016	$	3,742	$	—	$	6,694		$	2,014		$	12,450
Other⁽¹⁾	—		—		2			3			5
Balance as of December 31, 2017	$	3,742	$	—	$	6,696		$	2,017		$	12,455
Acquisition of Orbital ATK	418		5,256		469			79			6,222
Other⁽¹⁾	—		—		(2		)	(3		)	(5		)
Balance as of December 31, 2018	$	4,160	$	5,256	$	7,163		$	2,093		$	18,672


⁽¹⁾	Other consists primarily of adjustments for foreign currency translation.

Accumulated goodwill impairment losses at December 31, 2018 and 2017, totaled $570 million at Aerospace Systems.

Other Purchased Intangible Assets

Net customer-related and other intangible assets, including the fair value of purchased intangible assets acquired in the Merger, are as follows:



	December 31
$ in millions	2018			2017
Gross customer-related and other intangible assets	$	3,356		$	1,833
Less accumulated amortization	(1,984		)	(1,781		)
Net customer-related and other intangible assets	$	1,372		$	52

Amortization expense for 2018, 2017 and 2016, was $203 million, $14 million and $16 million, respectively. The company’s other purchased intangible assets are being amortized over an aggregate weighted-average period of 12 years. As of December 31, 2018, the expected future amortization of purchased intangibles for each of the next five years is as follows:



$ in millions
2019	$	331
2020	262
2021	204
2022	197
2023	78

Fair Value of Financial Instruments

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

9. FAIR VALUE OF FINANCIAL INSTRUMENTS

The company holds a portfolio of marketable securities consisting of securities to partially fund non-qualified employee benefit plans. A portion of these securities are held in common/collective trust funds and are measured at fair value using net asset value (NAV) per share as a practical expedient; and therefore are not required to be categorized in the fair value hierarchy table below. Marketable securities are included in Other non-current assets in the consolidated statements of financial position.

The company's derivative portfolio consists primarily of commodity forward contracts and foreign currency forward contracts. As a result of the Merger, the company assumed commodity forward contracts, which Innovation Systems periodically uses to hedge forecasted purchases of certain commodities. The contracts generally establish a fixed price for the underlying commodity and are designated and qualify as effective cash flow hedges of such commodity purchases. Commodity derivatives are valued based on prices of future exchanges and recently reported transactions in the marketplace. For foreign currency forward contracts, where model-derived valuations are appropriate, the company utilizes the income approach to determine the fair value and uses the applicable London Interbank Offered Rate (LIBOR) swap rates.

The following table presents the financial assets and liabilities the company records at fair value on a recurring basis identified by the level of inputs used to determine fair value. See Note 1 for the definitions of these levels.



	December 31, 2018								December 31, 2017
$ in millions	Level 1		Level 2			Total			Level 1		Level 2		Total
Financial Assets (Liabilities)
Marketable securities	$	319	$	1		$	320		$	352	$	1	$	353
Marketable securities valued using NAV	—		—			15			—		—		—
Total marketable securities	319		1			335			352		1		353
Derivatives	—		(10		)	(10		)	—		—		—

At December 31, 2018, the company had commodity forward contracts outstanding that hedge forecasted commodity purchases of 10 million pounds of copper and 4 million pounds of zinc. Gains or losses on the commodity forward contracts are recognized in product and service cost as the performance obligations on related contracts are satisfied.

The notional value of the company’s foreign currency forward contracts at December 31, 2018 and 2017 was $114 million and $89 million, respectively. At December 31, 2018, no portion of the notional value was designated as a cash flow hedge. The portion of the notional value designated as a cash flow hedge at December 31, 2017 was $8 million.

The derivative fair values and related unrealized gains/losses at December 31, 2018 and 2017 were not material.

There were no transfers of financial instruments between the three levels of the fair value hierarchy during the years ended December 31, 2018 and 2017.

The carrying value of cash and cash equivalents and commercial paper approximates fair value.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Long-Term Debt

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Long-Term Debt

10. DEBT

Unsecured Senior Notes

In October 2017, the company issued $8.25 billion of unsecured senior notes to finance the Orbital ATK Acquisition and to pay related fees and expenses as follows:


•	$1.0 billion of 2.08 percent Senior Notes due 2020 (the “2020 Notes”),


•	$1.5 billion of 2.55 percent Senior Notes due 2022 (the “2022 Notes”),


•	$1.5 billion of 2.93 percent Senior Notes due 2025 (the “2025 Notes”),


•	$2.0 billion of 3.25 percent Senior Notes due 2028 (the “2028 Notes”) and


•	$2.25 billion of 4.03 percent Senior Notes due 2047 (the “2047 Notes”).

In December 2016, the company issued $750 million of unsecured senior notes due February 1, 2027, with a fixed interest rate of 3.20 percent. We used the net proceeds from this offering for a debt repayment of $200 million in the fourth quarter of 2016 and for general corporate purposes.

Commercial Paper

In May 2018, the company commenced a commercial paper program that serves as a source of short-term financing. In September 2018, the company amended its commercial paper program to increase its capacity to issue unsecured commercial paper notes from $750 million up to $2.0 billion. The commercial paper notes outstanding have original maturities of three months or less from the date of issuance. At December 31, 2018, there were $198 million of outstanding short-term commercial paper borrowings at a weighted-average interest rate of 2.77 percent. The outstanding balance of commercial paper borrowings is recorded in Other current liabilities in the consolidated statements of financial position.

Credit Facilities

In August 2018, the company entered into a new five-year senior unsecured credit facility in an aggregate principal amount of $2.0 billion (the “2018 Credit Agreement”). The 2018 Credit Agreement replaced the company’s prior five-year revolving credit facility in an aggregate amount of $1.6 billion entered into on July 8, 2015. The revolving credit facility established under the 2018 Credit Agreement is intended to support the company’s commercial paper program and other general corporate purposes. At December 31, 2018, there was no balance outstanding under this facility; however, the outstanding balance of commercial paper borrowings reduces the amount available for borrowing under the 2018 Credit Agreement.

In December 2016, a subsidiary of the company entered into a two-year credit facility, with two additional one-year option periods, in an aggregate principal amount of £120 million (the equivalent of approximately $152 million as of December 31, 2018) (the “2016 Credit Agreement”). The company exercised the second option to extend the maturity to December 2020. The 2016 Credit Agreement is guaranteed by the company. At December 31, 2018, there was £85 million (the equivalent of approximately $108 million as of December 31, 2018) outstanding under this facility, which bears interest at a rate of LIBOR plus 1.10 percent. All of the borrowings outstanding under this facility mature less than one year from the date of issuance, but may be renewed under the terms of the facility. Based on our intent and ability to refinance the obligations on a long-term basis, substantially all of the borrowings are classified as non-current.

Our credit agreements contain generally customary terms and conditions, including covenants restricting the company’s ability to sell all or substantially all of its assets, merge or consolidate with another entity or undertake other fundamental changes and incur liens. The company also cannot permit the ratio of its debt to capitalization (as set forth in the credit agreements) to exceed 65 percent. At December 31, 2018, the company was in compliance with all covenants under its credit agreements.

Long-term debt consists of the following:



$ in millions		December 31
$ in millions		2018			2017
Fixed-rate notes and debentures, maturing in	Interest rate
2018	1.75%	$	—		$	850
2019	5.05%	500			500
2020	2.08%	1,000			1,000
2021	3.50%	700			700
2022	2.55%	1,500			1,500
2023	3.25%	1,050			1,050
2025	2.93%	1,500			1,500
2026	7.75% - 7.88%	527			527
2027	3.20%	750			750
2028	3.25%	2,000			2,000
2031	7.75%	466			466
2040	5.05%	300			300
2043	4.75%	950			950
2045	3.85%	600			600
2047	4.03%	2,250			2,250
Credit facilities	1.89%	108			134
Other	Various	272			271
Debt issuance costs		(73		)	(82		)
Total long-term debt		14,400			15,266
Less: current portion⁽¹⁾		517			867
Long-term debt, net of current portion		$	13,883		$	14,399

⁽¹⁾The current portion of long-term debt is recorded in Other current liabilities in the consolidated statements of financial position.

In connection with the Merger, the company assumed $1.7 billion of long-term debt, all of which was repaid as of December 31, 2018.

The estimated fair value of long-term debt was $14.3 billion and $16.0 billion as of December 31, 2018 and 2017, respectively. We calculated the fair value of long-term debt using Level 2 inputs, based on interest rates available for debt with terms and maturities similar to the company’s existing debt arrangements.

Indentures underlying long-term debt issued by the company or its subsidiaries contain various restrictions with respect to the issuer, including one or more restrictions relating to limitations on liens, sale-leaseback arrangements and funded debt of subsidiaries. The majority of these fixed rate notes and debentures are subject to redemption at the company’s discretion at any time prior to maturity in whole or in part at the principal amount plus any make-whole premium and accrued and unpaid interest. Interest on these fixed rate notes and debentures are payable semi-annually in arrears.

Total interest payments, net of interest received, were $456 million, $273 million, and $299 million for the years ended December 31, 2018, 2017 and 2016, respectively.

Maturities of long-term debt as of December 31, 2018, are as follows:



$ in millions
Year Ending December 31
2019	$	517
2020	1,127
2021	741
2022	1,505
2023	1,053
Thereafter	9,532
Total principal payments	14,475
Unamortized premium on long-term debt, net of discount	(2		)
Debt issuance costs	(73		)
Total long-term debt	$	14,400

Investigations, Claims and Litigation	12 Months Ended
Investigations, Claims and Litigation	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Investigations, Claims and Litigation	11. INVESTIGATIONS, CLAIMS AND LITIGATION Litigation On May 4, 2012, the company commenced an action, Northrop Grumman Systems Corp. v. United States, in the U.S. Court of Federal Claims. This lawsuit relates to an approximately $875 million firm fixed-price contract awarded to the company in 2007 by the U.S. Postal Service (USPS) for the construction and delivery of flats sequencing systems (FSS) as part of the postal automation program. The FSS have been delivered. The company’s lawsuit is based on various theories of liability. The complaint seeks approximately $63 million for unpaid portions of the contract price, and approximately $115 million based on the company’s assertions that, through various acts and omissions over the life of the contract, the USPS adversely affected the cost and schedule of performance and materially altered the company’s obligations under the contract. The United States responded to the company’s complaint with an answer, denying most of the company’s claims, and counterclaims seeking approximately $410 million, less certain amounts outstanding under the contract. The principal counterclaim alleges that the company delayed its performance and caused damages to the USPS because USPS did not realize certain costs savings as early as it had expected. On April 2, 2013, the U.S. Department of Justice informed the company of a False Claims Act complaint relating to the FSS contract that was filed under seal by a relator in June 2011 in the U.S. District Court for the Eastern District of Virginia. On June 3, 2013, the United States filed a Notice informing the Court that the United States had decided not to intervene in this case. The relator alleged that the company violated the False Claims Act in a number of ways with respect to the FSS contract, alleged damage to the USPS in an amount of at least approximately $179 million annually, alleged that he was improperly discharged in retaliation, and sought an unspecified partial refund of the contract purchase price, penalties, attorney’s fees and other costs of suit. The relator later voluntarily dismissed his retaliation claim and reasserted it in a separate arbitration, which he also ultimately voluntarily dismissed. On September 5, 2014, the court granted the company’s motion for summary judgment and ordered the relator’s False Claims Act case be dismissed with prejudice. On December 19, 2014, the company filed a motion for partial summary judgment asking the court to dismiss the principal counterclaim referenced above. On June 29, 2015, the Court heard argument and denied that motion without prejudice to filing a later motion to dismiss. On February 16, 2018, both the company and the United States filed motions to dismiss many of the claims and counterclaims in whole or in part. The United States also filed a motion seeking to amend its answer and counterclaim, including to reduce its counterclaim to approximately $193 million, which the court granted on June 11, 2018. On October 17, 2018, the court granted in part and denied in part the parties’ motions to dismiss. On December 17, 2018, the court issued a Scheduling Order, proposed by the parties, providing for the parties to engage in mediation through March 1, 2019, and for pretrial activities then to resume, if and as necessary, with trial to commence on or about September 23, 2019. Although the ultimate outcome of these matters (“the FSS matters,” collectively), including any possible loss, cannot be predicted or reasonably estimated at this time, the company intends vigorously to pursue and defend the FSS matters. On August 8, 2013, the company received a court-appointed expert’s report in litigation pending in the Second Federal Court of the Federal District in Brazil brought by the Brazilian Post and Telegraph Corporation (ECT), a Brazilian state-owned entity, against Solystic SAS (Solystic), a French subsidiary of the company, and two of its consortium partners. In this suit, commenced on December 17, 2004, and relatively inactive for some period of time, ECT alleges the consortium breached its contract with ECT and seeks damages of approximately R$111 million (the equivalent of approximately $29 million as of December 31, 2018), plus interest, inflation adjustments and attorneys’ fees, as authorized by Brazilian law, which amounts could be significant over time. The original suit sought R$89 million (the equivalent of approximately $23 million as of December 31, 2018) in damages. In October 2013, ECT asserted an additional damage claim of R$22 million (the equivalent of approximately $6 million as of December 31, 2018). In its counterclaim, Solystic alleges ECT breached the contract by wrongfully refusing to accept the equipment Solystic had designed and built and seeks damages of approximately €31 million (the equivalent of approximately $35 million as of December 31, 2018), plus interest, inflation adjustments and attorneys’ fees, as authorized by Brazilian law. The Brazilian court retained an expert to consider certain issues pending before it. On August 8, 2013 and September 10, 2014, the company received reports from the expert, which contain some recommended findings relating to liability and the damages calculations put forth by ECT. Some of the expert’s recommended findings were favorable to the company and others were favorable to ECT. In November 2014, the parties submitted comments on the expert’s most recent report. On June 16, 2015, the court published a decision denying the parties’ request to present oral testimony. In a decision dated November 13, 2018, the trial court ruled in ECT’s favor and awarded damages of R$41 million (the equivalent of approximately $11 million as of December 31, 2018) against Solystic and its consortium partners, with that amount to be adjusted for inflation and interest from November 2004 through any appeal, in accordance with the Manual of Calculations of the Federal Justice, as well as attorneys’ fees. Once the court officially publishes the decision, the parties will have 10 days to file a motion for clarification with the trial court or 30 days to file an appeal with the intermediate court of appeals. The company previously identified and disclosed to the U.S. government various issues relating primarily to time-charging practices of some employees working on a particular program with remote deployments. In the fourth quarter of 2018, the Department of Justice concluded its investigations as to the company and settled the matter with the company. As part of the settlement, the company paid a total of $30 million, largely in restitution and repayment, and agreed to continue to cooperate with the government’s ongoing investigation. We are engaged in remediation activities relating to environmental conditions allegedly resulting from historic operations at the former United States Navy and Grumman facilities in Bethpage, New York. For over 20 years, we have worked closely with the United States Navy, the United States Environmental Protection Agency, the New York State Department of Environmental Conservation, the New York State Department of Health and other federal, state and local governmental authorities, to address legacy environmental conditions in Bethpage. We have incurred, and expect to continue to incur, as included in Note 12, substantial remediation costs related to these environmental conditions. The remediation standards or requirements to which we are subject may change and costs may increase materially. The State of New York has notified us that it intends to seek to impose additional remedial requirements and, among other things, is evaluating natural resource damages. In addition, we are and may become a party to various legal proceedings and disputes related to remediation and/or alleged environmental impacts in Bethpage, including with federal and state entities, local municipalities and water districts, insurance carriers and class action and individual plaintiffs alleging personal injury and property damage. These Bethpage matters could result in additional costs, fines, penalties, sanctions, compensatory or other damages (including natural resource damages), determinations on allocation, allowability and coverage, and non-monetary relief. We cannot at this time predict or reasonably estimate the potential cumulative outcomes or ranges of possible liability of these aggregate Bethpage matters. On August 12, 2016, a putative class action complaint, naming Orbital ATK and two of its then-officers as defendants, Steven Knurr, et al. v. Orbital ATK, Inc., No. 16-cv-01031 (TSE-MSN), was filed in the United States District Court for the Eastern District of Virginia. The complaint asserts claims on behalf of purchasers of Orbital ATK securities for violations of Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5, allegedly arising out of false and misleading statements and the failure to disclose that: (i) Orbital ATK lacked effective control over financial reporting; and (ii) as a result, it failed to record an anticipated loss on a long-term contract with the U.S. Army to manufacture and supply small caliber ammunition at the U.S. Army's Lake City Army Ammunition Plant. On April 24, 2017 and October 10, 2017, the plaintiffs filed amended complaints naming additional defendants and asserting claims for alleged violations of additional sections of the Exchange Act and alleged false and misleading statements in Orbital ATK’s Form S-4 filed in connection with the Orbital-ATK Merger. The complaint seeks damages, reasonable costs and expenses at trial, including counsel and expert fees, and such other relief as deemed appropriate by the Court. On August 8, 2018, plaintiffs sought leave to file an additional amended complaint; defendants filed an opposition. The parties engaged in mediation on November 6, 2018. On December 27, 2018, the parties reached a preliminary agreement to resolve the litigation for $108 million, subject to agreement on additional terms and to court approval. On January 15, 2019, the court issued an order setting a schedule for final settlement approval proceedings. Consistent with that order, on January 30, 2019, the parties submitted a joint motion for preliminary settlement approval, with supporting documents. The schedule suggests a final approval settlement hearing in the second quarter of 2019. The company is also negotiating with and pursuing coverage litigation against various of its insurance carriers. The company intends vigorously to defend itself in connection with these matters. We currently expect related contingencies will continue to be included in the company’s measurement period adjustments of the fair value of assets acquired and liabilities assumed in the Merger (see Note 2). The SEC is investigating Orbital ATK’s historical accounting practices relating to the restatement of Orbital’s unaudited condensed consolidated financial statements for the quarterly periods ended July 5, 2015 and October 4, 2015 described in the Transition Report on Form 10-K for the nine-month period ending December 31, 2015 previously filed on March 15, 2016. The SEC is also investigating matters relating to a voluntary disclosure Orbital ATK made concerning the restatement described in Orbital ATK’s Form 10-K/A for the nine-month period ending December 31, 2015 filed on February 24, 2017. The ultimate outcome of these matters, including any possible loss, cannot be predicted or reasonably estimated at this time and the company intends to continue to cooperate with the SEC. The company is a party to various other investigations, lawsuits, arbitration, claims, enforcement actions and other legal proceedings, including government investigations and claims, that arise in the ordinary course of our business. The nature of legal proceedings is such that we cannot assure the outcome of any particular matter. However, based on information available to the company to date, the company does not believe that the outcome of any of these other matters pending against the company is likely to have a material adverse effect on the company’s consolidated financial position as of December 31, 2018, or its annual results of operations and/or cash flows.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

12. COMMITMENTS AND CONTINGENCIES

U.S. Government Cost Claims

From time to time, the company is advised of claims by the U.S. government concerning certain potential disallowed costs, plus, at times, penalties and interest. When such findings are presented, the company and U.S. government representatives engage in discussions to enable the company to evaluate the merits of these claims, as well as to assess the amounts being claimed. Where appropriate, provisions are made to reflect the company’s estimated exposure for such potential disallowed costs. Such provisions are reviewed periodically using the most recent information available. The company believes it has adequately reserved for disputed amounts that are probable and reasonably estimable, and that the outcome of any such matters would not have a material adverse effect on its consolidated financial position as of December 31, 2018, or its annual results of operations and/or cash flows.

Environmental Matters

The table below summarizes management’s estimate of the range of reasonably possible future costs for environmental remediation, the amount accrued within that range, and the deferred costs expected to be recoverable through overhead charges on U.S. government contracts as of December 31, 2018 and 2017:



$ in millions	Range of Reasonably Possible Future Costs⁽¹⁾	Accrued Costs⁽²⁾		Deferred Costs⁽³⁾
December 31, 2018	$447 - $835	$	461	$	343
December 31, 2017	405 - 792	410		207


⁽¹⁾	Estimated remediation costs are not discounted to present value. The range of reasonably possible future costs does not take into consideration amounts expected to be recoverable through overhead charges on U.S. government contracts.


⁽²⁾	As of December 31, 2018, $159 million is recorded in Other current liabilities and $302 million is recorded in Other non-current liabilities.


⁽³⁾	As of December 31, 2018, $127 million is deferred in Prepaid expenses and other current assets and $216 million is deferred in Other non-current assets. These amounts reflect a $103 million increase during 2018 in our estimated recovery of certain environmental remediation costs and are evaluated for recoverability on a routine basis.

As a result of the Merger, we assumed certain environmental remediation liabilities that are included in the accrued costs above, along with the related deferred costs expected to be recoverable on U.S. government contracts.

Although management cannot predict whether new information gained as our environmental remediation projects progress, or as changes in facts and circumstances occur, will materially affect the estimated liability accrued, except with respect to Bethpage, we do not anticipate that future remediation expenditures associated with our currently identified projects will have a material adverse effect on the company’s consolidated financial position as of December 31, 2018, or its annual results of operations and/or cash flows. With respect to Bethpage, as described in Note 11, we cannot at this time estimate the range of reasonably possible additional future costs that could result from potential changes to remediation standards or requirements to which we are subject.

Financial Arrangements

In the ordinary course of business, the company uses standby letters of credit and guarantees issued by commercial banks and surety bonds issued principally by insurance companies to guarantee the performance on certain obligations. At December 31, 2018, there were $542 million of stand-by letters of credit and guarantees and $201 million of surety bonds outstanding.

Indemnifications

The company has provided indemnification for certain environmental, income tax and other potential liabilities in connection with certain of its divestitures. The settlement of these liabilities is not expected to have a material adverse effect on the company’s consolidated financial position as of December 31, 2018, or its annual results of operations and/or cash flows.

Operating Leases

Rental expense for operating leases was $375 million, $300 million and $298 million in 2018, 2017 and 2016, respectively. These amounts are net of immaterial amounts of sublease rental income. Minimum rental commitments under long-term non-cancelable operating leases as of December 31, 2018 are payable as follows:



$ in millions
Year Ending December 31
2019	$	312
2020	270
2021	221
2022	186
2023	152
Thereafter	939
Total minimum lease payments	$	2,080

Retirement Benefits

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Retirement Benefits

13. RETIREMENT BENEFITS

Plan Descriptions

U.S. Defined Benefit Pension Plans – The company sponsors several defined benefit pension plans in the U.S. Pension benefits for most participants are based on their years of service, age and compensation. It is our policy to fund at least the minimum amount required for all qualified plans, using actuarial cost methods and assumptions acceptable under U.S. government regulations, by making payments into benefit trusts separate from the company.

U.S. Defined Contribution Plans – The company also sponsors defined contribution plans covering the majority of its employees, including certain employees covered under collective bargaining agreements. Company contributions vary depending on date of hire, with a majority of employees being eligible for employer matching of employee contributions. Based on date of hire, certain employees are eligible to receive a company non-elective contribution or an enhanced matching contribution in lieu of a defined benefit pension plan benefit. The company’s contributions to these defined contribution plans for the years ended December 31, 2018, 2017 and 2016, were $403 million, $344 million and $311 million, respectively.

Non-U.S. Benefit Plans – The company sponsors several benefit plans for non-U.S. employees. These plans are designed to provide benefits appropriate to local practice and in accordance with local regulations. Some of these plans are funded using benefit trusts separate from the company.

Medical and Life Benefits – The company provides a portion of the costs for certain health care and life insurance benefits for a substantial number of its active and retired employees. In addition to a company and employee cost-sharing feature, the health plans also have provisions for deductibles, co-payments, coinsurance percentages, out-of-pocket limits, conformance to a schedule of reasonable fees, the use of managed care providers and coordination of benefits with other plans. The plans also provide for a Medicare carve-out. The company reserves the right to amend or terminate the plans at any time.

Certain covered employees and dependents are eligible to participate in plans upon retirement if they meet specified age and years of service requirements. The company provides subsidies to reimburse certain retirees for a portion of the cost of individual Medicare-supplemental coverage purchased directly by the retiree through a private insurance exchange. The company has capped the amount of its contributions to substantially all of its remaining postretirement medical and life benefit plans. In addition, after January 1, 2005 (or earlier at some businesses), newly hired employees are not eligible for subsidized postretirement medical and life benefits.

Summary Plan Results

As discussed in Note 1, during the fourth quarter of 2018, we changed our accounting method related to the recognition of actuarial gains and losses for our pension and OPB plans. Under the new method, actuarial gains and losses are immediately recognized in net periodic benefit cost upon annual remeasurement in the fourth quarter, or on an interim basis as triggering events warrant remeasurement. These changes have been applied retrospectively to all prior years presented below. See Notes 1, 16, 17 and 18 for further information regarding the impact of the change in accounting principle on our consolidated financial statements.

The cost to the company of its retirement benefit plans is shown in the following table:



	Year Ended December 31
	Pension Benefits									Medical and Life Benefits
$ in millions	2018			2017			2016			2018			2017			2016
Components of net periodic benefit cost
Service cost	$	404		$	388		$	390		$	21		$	20		$	29
Interest cost	1,226			1,250			1,302			76			85			95
Expected return on plan assets	(2,217		)	(1,885		)	(1,853		)	(101		)	(89		)	(86		)
Amortization of prior service credit	(58		)	(57		)	(60		)	(21		)	(22		)	(22		)
Mark-to-market expense (benefit)	699			(445		)	1,041			(44		)	(91		)	(91		)
Other	—			(7		)	—			—			—			—
Net periodic benefit cost	$	54		$	(756	)	$	820		$	(69	)	$	(97	)	$	(75	)

Changes in Presentation

As discussed in Note 1, we adopted ASU 2017-07 on January 1, 2018 using the retrospective method, which changed the financial statement presentation of service costs and the other components of net periodic benefit cost. The service cost component continues to be included in operating income; however, the other components are now presented in Net FAS (non-service) pension benefit and MTM (expense) benefit in the consolidated statements of earnings and comprehensive income. In addition, interest on service cost, which has historically been included in service cost, is now presented in interest cost. Further, to conform our presentation of service costs for all plans, administrative expenses previously included in service cost for certain plans are now consistently presented in the MTM (expense) benefit component. As a result, the company reclassified interest on service cost of $16 million and $18 million and plan administrative expenses of $20 million and $38 million from service cost to the interest cost and MTM (expense) benefit components, respectively, for its pension plans for the years ended December 31, 2017 and 2016, respectively, to conform to the current year presentation. For the company’s medical and life benefit plans, plan administrative expenses of $2 million were reclassified from service cost to the MTM (expense) benefit component for the year ended December 31, 2017 and interest on service costs of $1 million were reclassified from service cost to the interest cost component for the year ended December 31, 2016 to conform to the current year presentation. This change in presentation had no impact on net periodic benefit cost.

The table below summarizes the components of changes in unamortized prior service credit for the years ended December 31, 2016, 2017 and 2018:



$ in millions	Pension Benefits			Medical and Life Benefits			Total
Changes in unamortized prior service credit
Amortization of prior service credit	$	60		$	22		$	82
Tax expense	(11		)	(9		)	(20		)
Change in unamortized prior service credit – 2016	49			13			62
Amortization of prior service credit	57			22			79
Tax expense	(26		)	(9		)	(35		)
Change in unamortized prior service credit – 2017	31			13			44
Amortization of prior service credit	58			21			79
Tax expense	(14		)	(5		)	(19		)
Change in unamortized prior service credit – 2018	$	44		$	16		$	60

We expect to recognize $59 million and $3 million of prior year service credit related to our pension benefit and medical and life benefit plans, respectively, in net periodic benefit cost in 2019.

The following table sets forth the funded status and amounts recognized in the consolidated statements of financial position for the company’s defined benefit retirement plans. Pension benefits data includes the qualified plans, foreign plans and U.S. unfunded non-qualified plans for benefits provided to directors, officers and certain employees. The company uses a December 31 measurement date for its plans.



	Pension Benefits						Medical and Life Benefits
$ in millions	2018			2017			2018			2017
Plan Assets
Fair value of plan assets at beginning of year	$	27,226		$	24,384		$	1,338		$	1,208
Net (loss) gain on plan assets	(1,043		)	3,885			(65		)	208
Employer contributions	370			596			38			45
Participant contributions	9			11			25			24
Benefits paid	(1,685		)	(1,617		)	(148		)	(144		)
Acquired plan assets	2,293			—			58			—
Other	(20		)	(33		)	1			(3		)
Fair value of plan assets at end of year	27,150			27,226			1,247			1,338
Projected Benefit Obligation
Projected benefit obligation at beginning of year	31,967			30,409			2,110			2,100
Service cost	404			388			21			20
Interest cost	1,226			1,250			76			85
Participant contributions	9			11			25			24
Actuarial loss (gain)	(2,561		)	1,544			(211		)	26
Benefits paid	(1,685		)	(1,617		)	(148		)	(144		)
Acquired benefit obligation	2,895			—			50			—
Other	(24		)	(18		)	7			(1		)
Projected benefit obligation at end of year	32,231			31,967			1,930			2,110
Funded status	$	(5,081	)	$	(4,741	)	$	(683	)	$	(772	)

Classification of amounts recognized in the consolidated statements of financial position
Non-current assets	$	77		$	82		$	124		$	112
Current liability	(164		)	(154		)	(46		)	(42		)
Non-current liability	(4,994		)	(4,669		)	(761		)	(842		)

The accumulated benefit obligation for all defined benefit pension plans was $31.9 billion and $31.6 billion at December 31, 2018 and 2017, respectively.

Amounts for pension plans with accumulated benefit obligations in excess of fair value of plan assets are as follows:



	December 31
$ in millions	2018		2017
Projected benefit obligation	$	30,259	$	29,804
Accumulated benefit obligation	29,961		29,454
Fair value of plan assets	25,101		24,981

Plan Assumptions

On a weighted-average basis, the following assumptions were used to determine benefit obligations and net periodic benefit cost:



	Pension Benefits				Medical and Life Benefits
	2018		2017		2018		2017
Assumptions used to determine benefit obligation at December 31
Discount rate	4.31	%	3.68	%	4.30	%	3.66	%
Initial cash balance crediting rate assumed for the next year	3.00	%	2.75	%
Rate to which the cash balance crediting rate is assumed to increase (the ultimate rate)	3.25	%	3.00	%
Year that the cash balance crediting rate reaches the ultimate rate	2024		2023
Rate of compensation increase	3.00	%	3.00	%
Initial health care cost trend rate assumed for the next year					6.20	%	6.50	%
Rate to which the health care cost trend rate is assumed to decline (the ultimate trend rate)					5.00	%	5.00	%
Year that the health care cost trend rate reaches the ultimate trend rate					2023		2023
Assumptions used to determine benefit cost for the year ended December 31
Discount rate	3.68	%	4.19	%	3.66	%	4.13	%
Initial cash balance crediting rate assumed for the next year	2.75	%	3.10	%
Rate to which the cash balance crediting rate is assumed to increase (the ultimate rate)	3.00	%	3.60	%
Year that the cash balance crediting rate reaches the ultimate rate	2023		2022
Expected long-term return on plan assets	8.00	%	8.00	%	7.65	%	7.70	%
Rate of compensation increase	3.00	%	3.00	%
Initial health care cost trend rate assumed for the next year					6.50	%	6.50	%
Rate to which the health care cost trend rate is assumed to decline (the ultimate trend rate)					5.00	%	5.00	%
Year that the health care cost trend rate reaches the ultimate trend rate					2023		2020

Plan Assets and Investment Policy

Plan assets are invested in various asset classes that are expected to produce a sufficient level of diversification and investment return over the long term. Through consultation with our investment management team and outside investment advisers, management develops expected long-term returns for each of the plans’ strategic asset classes. In addition to our historical investment performance, we consider several factors, including current market data such as yields/price-earnings ratios, historical market returns over long periods and periodic surveys of investment managers’ expectations. Using policy target allocation percentages and the asset class expected returns, we calculate a weighted-average expected long-term rate of return. Liability studies are conducted on a regular basis to provide guidance in setting investment goals with an objective to balance risk. Risk targets are established and monitored against acceptable ranges.

Our investment policies and procedures are designed to ensure the plans’ investments are in compliance with the Employee Retirement Income Security Act (ERISA). Guidelines are established defining permitted investments within each asset class. Derivatives are used for transitioning assets, asset class rebalancing, managing currency risk and for management of fixed-income and alternative investments.

For the majority of the plans’ assets, the investment policies require that the asset allocation be maintained within the following ranges as of December 31, 2018:



		Asset Allocation Ranges
Cash and cash equivalents		0% - 12%
Global Public Equities		35% - 55%
Fixed-income securities		20% - 40%
Alternative investments		13% - 33%

The table below provides the fair values of the company’s pension and Voluntary Employee Beneficiary Association (VEBA) trust plan assets at December 31, 2018 and 2017, by asset category. The table also identifies the level of inputs used to determine the fair value of assets in each category. See Note 1 for the definitions of these levels. Certain investments that are measured at fair value using NAV per share (or its equivalent) as a practical expedient are not required to be categorized in the fair value hierarchy table. The total fair value of these investments is included in the table below to permit reconciliation of the fair value hierarchy to amounts presented in the funded status table above. As of December 31, 2018 and 2017, there were no investments expected to be sold at a value materially different than NAV.



	Level 1				Level 2				Level 3				Total
$ in millions	2018		2017		2018		2017		2018		2017		2018		2017
Asset category
Cash and cash equivalents	$	209	$	55	$	2,655	$	4,086					$	2,864	$	4,141
U.S. equities	2,859		3,365								$	1	2,859		3,366
International equities	2,711		2,453						$	1	1		2,712		2,454
Fixed-income securities
U.S. Treasuries	26		—		1,501		1,282						1,527		1,282
U.S. Government Agency					322		345						322		345
Non-U.S. Government					206		135						206		135
Corporate debt	34		—		4,141		4,406						4,175		4,406
Asset backed					297		255						297		255
High yield debt	11		—		153		866						164		866
Bank loans					20		248						20		248
Other Assets	15		15		51		3		2		2		68		20
Investments valued using NAV as a practical expedient
U.S. equities													1,170		1,053
International equities													4,017		4,315
Fixed-income funds													1,386		129
Hedge funds													351		166
Opportunistic investments													1,367		873
Private equities													2,510		2,091
Real estate funds													2,382		2,419
Fair value of plan assets at the end of the year	$	5,865	$	5,888	$	9,346	$	11,626	$	3	$	4	$	28,397	$	28,564

There were no transfers of plan assets between the three levels of the fair value hierarchy during the years ended December 31, 2018 and 2017.

Generally, investments are valued based on information in financial publications of general circulation, statistical and valuation services, records of security exchanges, appraisal by qualified persons, transactions and bona fide offers. Cash and cash equivalents are predominantly held in money market or short-term investment funds. U.S. and international equities consist primarily of common stocks and institutional common trust funds. Investments in certain equity securities, which include domestic and international securities and registered investment companies, and exchange-traded funds with fixed income strategies are valued at the last reported sales or quoted price on the last business day of the reporting period. Fair values for certain fixed-income securities, which are not exchange-traded, are valued using third-party pricing services.

Other assets include derivative assets with a fair value of $76 million and $34 million, derivative liabilities with a fair value of $52 million and $19 million, and net notional amounts of $3.2 billion and $3.3 billion, as of December 31, 2018 and 2017, respectively. Derivative instruments may include exchange traded futures contracts, interest rate swaps, options on futures and swaps, currency contracts, total return swaps and credit default swaps. Notional amounts do not quantify risk or represent assets or liabilities of the pension and VEBA trusts, but are used in the calculation of cash settlement under the contracts. The volume of derivative activity is commensurate with the amounts disclosed at year-end. Certain derivative financial instruments within the pension trust are subject to master netting agreements with certain counterparties.

Investments in certain equity and fixed-income funds, which include common/collective trust funds, and alternative investments, including hedge funds, opportunistic investments, private equity funds and real estate funds, are valued based on the NAV derived by the investment managers, as a practical expedient, and are described further below.

U.S. and International equities: Generally, redemption periods are daily or monthly with a notice requirement less than 30 days. As of December 31, 2018 and 2017, there were no unfunded commitments.

Fixed-income funds: Redemption periods are daily, monthly or quarterly with various notice requirements but generally are less than 30 days. As of December 31, 2018 and 2017, there were no unfunded commitments.

Hedge funds: The redemption period of hedge funds is generally monthly or quarterly with various notice requirements from 30 to 95 days. As of December 31, 2018 and 2017, there were no unfunded commitments.

Opportunistic investments: Opportunistic investments are primarily held in partnerships with a 5-10 year life. As of December 31, 2018 and 2017, unfunded commitments were $1.1 billion and $768 million, respectively.

Private equities: The term of each fund is typically 10 or more years and the fund’s investors do not have an option to redeem their interest in the fund. As of December 31, 2018 and 2017, unfunded commitments were $1.8 billion and $1.4 billion, respectively.

Real estate funds: Consists of closed-end real estate funds and infrastructure funds with terms that are typically 10 or more years. This class also contains open-end funds that generally allow investors to redeem their interests in the fund. As of December 31, 2018 and 2017, unfunded commitments were $73 million and $71 million, respectively.

For the years ended December 31, 2018 and 2017, the defined benefit pension and VEBA trusts did not hold any Northrop Grumman common stock.

Benefit Payments

The following table reflects estimated future benefit payments for the next ten years, based upon the same assumptions used to measure the benefit obligation, and includes expected future employee service, as of December 31, 2018:



$ in millions	Pension Plans		Medical and Life Plans		Total
Year Ending December 31
2019	$	1,781	$	153	$	1,934
2020	1,834		155		1,989
2021	1,880		142		2,022
2022	1,928		141		2,069
2023	1,970		139		2,109
2024 through 2028	10,384		651		11,035

In 2019, the company expects to contribute the required minimum funding of approximately $91 million to its pension plans and approximately $50 million to its medical and life benefit plans. During the year ended December 31, 2018, the company made voluntary pension contributions of $280 million.

Stock Compensation Plans and Other Compensation Arrangements

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock Compensation Plans and Other Compensation Arrangements

14. STOCK COMPENSATION PLANS AND OTHER COMPENSATION ARRANGEMENTS

Stock Compensation Plans

At December 31, 2018, the company had stock-based compensation awards outstanding under the following shareholder-approved plans: the 2011 Long-Term Incentive Stock Plan (2011 Plan), applicable to employees, and the 1993 Stock Plan for Non-Employee Directors (1993 SPND).

Employee Plans – In May 2015, the company’s shareholders approved amendments to the 2011 Plan. These amendments provided that shares issued under the plan would be counted against the aggregate share limit on a one-for-one basis. As amended, 5.1 million shares plus 2.4 million of newly authorized shares were available for issuance under the 2011 Plan; as of December 31, 2018, 5.9 million shares remain available for issuance.

The 2011 Plan provides for the following equity awards: stock options, stock appreciation rights (SARs) and stock awards. Under the 2011 Plan, no SARs have been granted and there are no outstanding stock options. Stock awards include restricted performance stock rights (RPSR) and restricted stock rights (RSR). RPSRs generally vest and are paid following the completion of a three-year performance period, based primarily on achievement of financial objectives determined by the Board. RSRs generally vest 100% after three years. Each includes dividend equivalents, which are paid upon payment of the RPSR or RSR. The terms of equity awards granted under the 2011 Plan provide for accelerated vesting, and in some instances forfeiture, of all or a portion of an award upon termination of employment.

Non-Employee Director Plans – Awards to non-employee directors are made pursuant to the Northrop Grumman Corporation Equity Grant Program for Non-Employee Directors under the 2011 Plan (the Director Program), which was amended and restated effective January 1, 2016. Prior to January 1, 2016, the Director Program and the 1993 SPND provided for quarterly award and vesting of an annual equity retainer in the form of deferred stock units (Automatic Stock Units) to be paid upon the conclusion of a director’s board service, or earlier, as specified by the director, if the director had five or more years of service.

Under the amended Director Program, each non-employee director is awarded an annual equity grant in the form of Automatic Stock Units, which vest on the one-year anniversary of the grant date. Directors may elect to have all or any portion of their Automatic Stock Units paid on (A) the earlier of (i) the beginning of a specified calendar year after the vesting date or (ii) their separation from service as a member of the Board, or (B) on the vesting date.

Directors also may elect to defer to a later year all or a portion of their remaining cash retainer or committee retainer fees into a stock unit account as Elective Stock Units or in alternative investment options. Elective Stock Units are awarded on a quarterly basis. Directors may elect to have all or a portion of their Elective Stock Units paid on the earlier of (i) the beginning of a specified calendar year or (ii) their separation from service as a member of the Board. Stock units awarded under the Director Program are paid out in an equivalent number of shares of Northrop Grumman common stock. Directors are credited with dividend equivalents in connection with the accumulated stock units until the shares of common stock relating to such stock units are issued.

Compensation Expense

Stock-based compensation expense for the years ended December 31, 2018, 2017 and 2016 was $86 million, $94 million and $93 million, respectively. The related tax benefits for stock-based compensation for the years ended December 31, 2018, 2017 and 2016 were $27 million, $48 million and $85 million, respectively.

At December 31, 2018, there was $108 million of unrecognized compensation expense related to unvested stock awards granted under the company’s stock-based compensation plans. These amounts are expected to be charged to expense over a weighted-average period of 1.3 years.

Stock Awards

Compensation expense for stock awards is measured at the grant date based on the fair value of the award and is recognized over the vesting period (generally three years). The fair value of stock awards and performance stock awards is determined based on the closing market price of the company’s common stock on the grant date. The fair value of market-based stock awards is determined at the grant date using a Monte Carlo simulation model. For purposes of measuring compensation expense for performance awards, the number of shares ultimately expected to vest is estimated at each reporting date based on management’s expectations regarding the relevant performance criteria.

Stock award activity for the years ended December 31, 2016, 2017 and 2018, is presented in the table below. Vested awards do not include any adjustments to reflect the final performance measure for issued shares.



	Stock Awards (in thousands)		Weighted- Average Grant Date Fair Value Per Share		Weighted- Average Remaining Contractual Term (in years)
Outstanding at January 1, 2016	1,586		$	122	1.2
Granted	483		186
Vested	(872	)	97
Forfeited	(49	)	143
Outstanding at December 31, 2016	1,148		$	167	1.3
Granted	397		233
Vested	(521	)	152
Forfeited	(86	)	198
Outstanding at December 31, 2017	938		$	192	1.0
Granted	376		321
Vested	(455	)	181
Forfeited	(63	)	250
Outstanding at December 31, 2018	796		$	244	0.8

The majority of our stock awards are granted annually during the first quarter.

The grant date fair value of shares issued in settlement of fully vested stock awards was $93 million, $96 million and $97 million during the years ended December 31, 2018, 2017 and 2016, respectively.

Cash Awards

The company grants certain employees cash units (CUs) and cash performance units (CPUs). Depending on actual performance against financial objectives, recipients of CPUs earn between 0 and 200 percent of the original grant. The following table presents the minimum and maximum aggregate payout amounts related to those cash awards granted for the periods presented:



	Year Ended December 31
$ in millions	2018		2017		2016
Minimum aggregate payout amount	$	36	$	38	$	39
Maximum aggregate payout amount	205		201		199

The majority of our cash awards are granted annually during the first quarter. CUs typically vest and settle in cash on the third anniversary of the grant date, while CPUs generally vest and pay out in cash based primarily on the achievement of financial metrics over a three-year period. At December 31, 2018, there was $137 million of unrecognized compensation expense related to cash awards.

Segment Information

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Segment Information

15. SEGMENT INFORMATION

The company is aligned in four operating sectors, which also comprise our reportable segments: Aerospace Systems, Innovation Systems, Mission Systems and Technology Services.

The following table presents sales and operating income by segment:



	Year Ended December 31
$ in millions	2018			2017			2016
Sales
Aerospace Systems	$	13,096		$	12,131		$	10,853
Innovation Systems	3,276			—			—
Mission Systems	11,709			11,470			11,161
Technology Services	4,297			4,687			4,765
Intersegment eliminations	(2,283		)	(2,284		)	(2,073		)
Total sales	30,095			26,004			24,706
Operating income
Aerospace Systems	1,411			1,289			1,198
Innovation Systems	343			—			—
Mission Systems	1,520			1,442			1,468
Technology Services	443			449			456
Intersegment eliminations	(270		)	(277		)	(258		)
Total segment operating income	3,447			2,903			2,864
Net FAS (service)/CAS pension adjustment	613			638			457
Unallocated corporate expense	(277		)	(319		)	(39		)
Other	(3		)	(4		)	(5		)
Total operating income	$	3,780		$	3,218		$	3,277

Net FAS (Service)/CAS Pension Adjustment

For financial statement purposes, we account for our employee pension plans in accordance with FAS. However, the cost of these plans is charged to our contracts in accordance with the FAR and the related CAS. The net FAS (service)/CAS pension adjustment reflects the difference between CAS pension expense included as cost in segment operating income and the service cost component of FAS expense included in total operating income.

Unallocated Corporate Expense

Unallocated corporate expense includes the portion of corporate costs not considered allowable or allocable under applicable CAS or FAR, and therefore not allocated to the segments, such as a portion of management and administration, legal, environmental, compensation, retiree benefits and other corporate unallowable costs. Unallocated corporate expense also includes costs not considered part of management’s evaluation of segment operating performance, such as amortization of purchased intangible assets and the additional depreciation expense related to the step-up in fair value of property, plant and equipment acquired through business combinations.

Disaggregation of Revenue



Sales by Customer Type	Year Ended December 31
	2018				2017				2016
$ in millions	$		%⁽³⁾		$		%⁽³⁾		$		%⁽³⁾
Aerospace Systems
U.S. Government ⁽¹⁾	$	11,380	87	%	$	10,521	87	%	$	9,277	86	%
International ⁽²⁾	1,371		10	%	1,160		10	%	1,192		11	%
Other Customers	148		1	%	155		1	%	144		1	%
Intersegment sales	197		2	%	295		2	%	240		2	%
Aerospace Systems sales	13,096		100	%	12,131		100	%	10,853		100	%
Innovation Systems
U.S. Government ⁽¹⁾	2,241		68	%	—		—		—		—
International ⁽²⁾	615		19	%	—		—		—		—
Other Customers	293		9	%	—		—		—		—
Intersegment sales	127		4	%	—		—		—		—
Innovation Systems sales	3,276		100	%	—		—		—		—
Mission Systems
U.S. Government ⁽¹⁾	8,803		75	%	8,876		77	%	8,737		78	%
International ⁽²⁾	1,647		14	%	1,540		14	%	1,416		13	%
Other Customers	114		1	%	100		1	%	133		1	%
Intersegment sales	1,145		10	%	954		8	%	875		8	%
Mission Systems sales	11,709		100	%	11,470		100	%	11,161		100	%
Technology Services
U.S. Government ⁽¹⁾	2,372		55	%	2,572		55	%	2,722		57	%
International ⁽²⁾	801		19	%	752		16	%	687		15	%
Other Customers	310		7	%	328		7	%	398		8	%
Intersegment sales	814		19	%	1,035		22	%	958		20	%
Technology Services sales	4,297		100	%	4,687		100	%	4,765		100	%
Total
U.S. Government ⁽¹⁾	24,796		82	%	21,969		85	%	20,736		84	%
International ⁽²⁾	4,434		15	%	3,452		13	%	3,295		13	%
Other Customers	865		3	%	583		2	%	675		3	%
Total Sales	$	30,095	100	%	$	26,004	100	%	$	24,706	100	%


⁽¹⁾	Sales to the U.S. government include sales from contracts for which we are the prime contractor, as well as those for which we are a subcontractor and the ultimate customer is the U.S. government. Each of the company’s segments derives substantial revenue from the U.S. government.

⁽²⁾ International sales include sales from contracts for which we are the prime contractor, as well as those for which we are a subcontractor and the ultimate customer is an international customer. These sales include foreign military sales contracted through the U.S. government.

⁽³⁾ Percentages calculated based on total segment sales.



Sales by Contract Type	Year Ended December 31
	2018				2017				2016
$ in millions	$		%⁽¹⁾		$		%⁽¹⁾		$		%⁽¹⁾
Aerospace Systems
Cost-type	$	7,634	59	%	$	7,193	61	%	$	6,484	61	%
Fixed-price	5,265		41	%	4,643		39	%	4,129		39	%
Intersegment sales	197				295				240
Aerospace System sales	13,096				12,131				10,853
Innovation Systems
Cost-type	843		27	%	—		—		—		—
Fixed-price	2,306		73	%	—		—		—		—
Intersegment sales	127				—				—
Innovation System sales	3,276				—				—
Mission Systems
Cost-type	4,939		47	%	5,311		51	%	5,200		51	%
Fixed-price	5,625		53	%	5,205		49	%	5,086		49	%
Intersegment sales	1,145				954				875
Mission System sales	11,709				11,470				11,161
Technology Services
Cost-type	1,588		46	%	1,693		46	%	1,770		46	%
Fixed-price	1,895		54	%	1,959		54	%	2,037		54	%
Intersegment sales	814				1,035				958
Technology Services sales	4,297				4,687				4,765
Total
Cost-type	15,004		50	%	14,197		55	%	13,454		54	%
Fixed-price	15,091		50	%	11,807		45	%	11,252		46	%
Total Sales	$	30,095			$	26,004			$	24,706


⁽¹⁾	Percentages calculated based on external customer sales.



Sales by Geographic Region	Year Ended December 31
	2018				2017				2016
$ in millions	$		%⁽²⁾		$		%⁽²⁾		$		%⁽²⁾
Aerospace Systems
United States	$	11,528	89	%	$	10,676	90	%	$	9,421	89	%
Asia/Pacific	705		6	%	649		6	%	579		5	%
All other ⁽¹⁾	666		5	%	511		4	%	613		6	%
Intersegment sales	197				295				240
Aerospace Systems sales	13,096				12,131				10,853
Innovation Systems
United States	2,534		80	%	—		—		—		—
Asia/Pacific	151		5	%	—		—		—		—
All other ⁽¹⁾	464		15	%	—		—		—		—
Intersegment sales	127				—				—
Innovation Systems sales	3,276				—				—
Mission Systems
United States	8,917		85	%	8,976		86	%	8,870		86	%
Asia/Pacific	659		6	%	671		6	%	514		5	%
All other ⁽¹⁾	988		9	%	869		8	%	902		9	%
Intersegment sales	1,145				954				875
Mission Systems sales	11,709				11,470				11,161
Technology Services
United States	2,682		77	%	2,900		79	%	3,120		82	%
Asia/Pacific	151		4	%	141		4	%	119		3	%
All other ⁽¹⁾	650		19	%	611		17	%	568		15	%
Intersegment sales	814				1,035				958
Technology Services sales	4,297				4,687				4,765
Total
United States	25,661		85	%	22,552		87	%	21,411		87	%
Asia/Pacific	1,666		6	%	1,461		5	%	1,212		5	%
All other ⁽¹⁾	2,768		9	%	1,991		8	%	2,083		8	%
Total Sales	$	30,095			$	26,004			$	24,706


⁽¹⁾	All other is principally comprised of Europe and the Middle East.


⁽²⁾	Percentages calculated based on external customer sales.

Intersegment Sales and Operating Income

Sales between segments are recorded at values that include intercompany operating income for the performing segment based on that segment’s estimated average operating margin rate for external sales. Such intercompany operating income is eliminated in consolidation, so that the company’s total sales and total operating income reflect only those transactions with external customers. See Note 1 for additional information.

The following table presents intersegment sales and operating income before eliminations:



	Year Ended December 31
$ in millions	2018					2017					2016
	Sales		Operating Income			Sales		Operating Income			Sales		Operating Income
Intersegment sales and operating income
Aerospace Systems	$	197		$	23	$	295		$	33	$	240		$	28
Innovation Systems	127			1		—			—		—			—
Mission Systems	1,145			165		954			141		875			136
Technology Services	814			81		1,035			103		958			94
Total	$	2,283		$	270	$	2,284		$	277	$	2,073		$	258

Assets

Substantially all of the company’s operating assets are located in the U.S. The following table presents assets by segment:



	December 31
$ in millions	2018		2017
Assets
Aerospace Systems	$	9,750	$	8,497
Innovation Systems	10,368		—
Mission Systems	11,047		10,389
Technology Services	2,957		3,014
Segment assets	34,122		21,900
Corporate assets⁽¹⁾	3,531		13,228
Total assets	$	37,653	$	35,128


⁽¹⁾	Corporate assets principally consist of cash and cash equivalents, property, plant and equipment and marketable securities.

Capital Expenditures and Depreciation and Amortization

The following table presents capital expenditures and depreciation and amortization by segment:



	Year Ended December 31
$ in millions	2018		2017		2016		2018		2017		2016
	Capital Expenditures						Depreciation and Amortization⁽¹⁾
Aerospace Systems	$	781	$	665	$	451	$	243	$	234	$	216
Innovation Systems	141		—		—		84		—		—
Mission Systems	206		164		372		134		131		140
Technology Services	18		15		6		45		40		37
Corporate	103		84		91		294		70		63
Total	$	1,249	$	928	$	920	$	800	$	475	$	456


⁽¹⁾	Beginning in 2018, corporate amounts include the amortization of other purchased intangible assets and the additional depreciation expense related to the step-up in fair value of property, plant and equipment acquired through business combinations as they are not considered part of management's evaluation of segment operating performance.

Unaudited Selected Quarterly Data

12 Months Ended

Dec. 31, 2018

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information [Text Block]

Unaudited quarterly financial results are set forth in the following tables. It is legacy Northrop Grumman’s long-standing practice to establish actual interim closing dates using a “fiscal” calendar in which we close our books on a Friday near each quarter-end date, in order to normalize the potentially disruptive effects of quarterly closings on business processes. Similarly, Innovation Systems uses a “fiscal” calendar by closing its books on a Sunday near these quarter-end dates and will continue this practice until its business processes are aligned with legacy Northrop Grumman’s. This practice is only used at interim periods within a reporting year.



2018
In millions, except per share amounts	1st Qtr		2nd Qtr⁽¹⁾		3rd Qtr⁽¹⁾		4th Qtr⁽¹⁾
Sales	$	6,735	$	7,119	$	8,085	$	8,156
Operating income	848		817		1,172		943
Net earnings	840		789		1,244		356

Basic earnings per share	4.82		4.52		7.15		2.07
Diluted earnings per share	4.79		4.50		7.11		2.06

Weighted-average common shares outstanding	174.3		174.5		174.1		171.8
Weighted-average diluted shares outstanding	175.4		175.4		174.9		172.6



2018 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(6		)	(6		)	(6		)	23
Net earnings	101			100			100			(394		)

Basic earnings per share	0.58			0.57			0.58			(2.29		)
Diluted earnings per share	0.58			0.57			0.57			(2.28		)



2017
In millions, except per share amounts	1st Qtr		2nd Qtr		3rd Qtr		4th Qtr
Sales	$	6,410	$	6,473	$	6,569	$	6,552
Operating income	853		864		829		672
Net earnings	770		677		750		672

Basic earnings per share	4.41		3.88		4.31		3.86
Diluted earnings per share	4.37		3.86		4.28		3.83

Weighted-average common shares outstanding	174.8		174.5		174.2		174.2
Weighted-average diluted shares outstanding	176.1		175.5		175.3		175.5



2017 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(9		)	(9		)	(8		)	(32		)
Net earnings	120			122			107			525

Basic earnings per share	0.69			0.70			0.62			3.01
Diluted earnings per share	0.68			0.70			0.61			2.99

⁽¹⁾ Selected financial data includes the operating results of Innovation Systems subsequent to the Merger date.

⁽²⁾ Table reflects the effects of the Accounting change described in Note 1 on our unaudited selected quarterly financial data.

2018 Impact of Accounting Method Change

12 Months Ended

Dec. 31, 2018

Accounting Changes and Error Corrections [Abstract]

Accounting Changes [Text Block]

17. 2018 IMPACT OF ACCOUNTING METHOD CHANGE

The following tables summarize the effects of the Accounting change described in Note 1 on our consolidated statement of earnings and comprehensive income, statement of cash flows and statement of changes in shareholders’ equity for the year ended December 31, 2018 and consolidated statement of financial position as of December 31, 2018:



CONSOLIDATED STATEMENT OF EARNINGS AND COMPREHENSIVE INCOME
	Year Ended December 31, 2018
$ in millions, except per share amounts	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Operating income	$	3,775		$	5		$	3,780
Other (expense) income
Interest expense	(562		)	—			(562		)
Net FAS (non-service) pension benefit	514			535			1,049
Mark-to-market pension and OPB expense	—			(655		)	(655		)
Other, net	132			(2		)	130
Earnings before income taxes	3,859			(117		)	3,742
Federal and foreign income tax expense	537			(24		)	513
Net earnings	$	3,322		$	(93	)	$	3,229
Basic earnings per share	$	19.12		$	(0.53	)	$	18.59
Diluted earnings per share	$	19.03		$	(0.54	)	$	18.49

CONSOLIDATED STATEMENT OF FINANCIAL POSITION
	December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Retained earnings	$	13,965		$	(5,897	)	$	8,068
Accumulated other comprehensive (loss) income	(5,949		)	5,897			(52		)



CONSOLIDATED STATEMENT OF CASH FLOWS
	December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Operating activities
Net earnings	$	3,322		$	(93	)	$	3,229
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	800			—			800
Mark-to-market pension and OPB expense	—			655			655
Stock-based compensation	86			—			86
Deferred income taxes	263			(29		)	234
Changes in assets and liabilities:
Accounts receivable, net	202			—			202
Unbilled receivables, net	(297		)	—			(297		)
Inventoried costs, net	(37		)	—			(37		)
Prepaid expenses and other assets	(56		)	—			(56		)
Accounts payable and other liabilities	381			—			381
Income taxes payable, net	(258		)	—			(258		)
Retiree benefits⁽¹⁾	(550		)	(533		)	(1,083		)
Other, net	(29		)	—			(29		)
Net cash provided by operating activities	$	3,827		$	—		$	3,827


⁽¹⁾	Includes company contributions to our pension and OPB plans as well as net periodic benefit costs, excluding MTM pension and OPB expense, which is presented as a separate non-cash item above.



CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS’ EQUITY
	Year ended December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Retained earnings
Beginning of year	$	11,632		$	(4,719	)	$	6,913
Impact from adoption of ASU 2018-02 and ASU 2016-01	1,064			(1,085		)	(21		)
Common stock repurchased	(1,225		)	—			(1,225		)
Net earnings	3,322			(93		)	3,229
Dividends declared	(822		)	—			(822		)
Stock compensation	(6		)	—			(6		)
End of year	13,965			(5,897		)	8,068
Accumulated other comprehensive (loss) income
Beginning of year	(4,718		)	4,719			1
Impact from adoption of ASU 2018-02 and ASU 2016-01	(1,064		)	1,085			21
Other comprehensive loss, net of tax	(167		)	93			(74		)
End of year	$	(5,949	)	$	5,897		$	(52	)

Recast 2017 and 2016 Financial Information

12 Months Ended

Dec. 31, 2018

Accounting Changes and Error Corrections [Abstract]

Accounting Changes and Error Corrections [Text Block]

18. RECAST 2017 AND 2016 FINANCIAL INFORMATION

Our prior period consolidated financial statements were recast for the retrospective adoption of ASC Topic 606 and ASU 2017-07 and the Accounting change described in Note 1. The following tables summarize the effects of these changes on our consolidated statements of earnings and comprehensive income, statements of cash flows and statements of changes in shareholders’ equity for the years ended December 31, 2017 and 2016 and consolidated statement of financial position as of December 31, 2017.

CONSOLIDATED STATEMENT OF EARNINGS AND COMPREHENSIVE INCOME



	Year Ended December 31, 2017
	As Previously Reported			Impact of:										As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			ASU 2017-07			Accounting Change			As Adjusted
Sales
Product	$	16,038			$	326		$	—		$	—		$	16,364
Service	9,765				(125		)	—			—			9,640
Total sales	25,803				201			—			—			26,004
Operating costs and expenses
Product	12,271				239			(18		)	35			12,527
Service	7,578				(42		)	(12		)	23			7,547
General and administrative expenses	2,655				57			—			—			2,712
Operating income	3,299				(53		)	30			(58		)	3,218
Other (expense) income
Interest expense	(360		)		—			—			—			(360		)
Net FAS (non-service) pension (expense) income	—				—			(44		)	743			699
Mark-to-market pension and OPB benefit	—				—			—			536			536
Other, net	110				—			14			12			136
Earnings before income taxes	3,049				(53		)	—			1,233			4,229
Federal and foreign income tax expense (benefit)	1,034				(33		)	—			359			1,360
Net earnings	$	2,015			$	(20	)	$	—		$	874		$	2,869

Basic earnings per share	$	11.55			$	(0.11	)	$	—		$	5.01		$	16.45
Weighted-average common shares outstanding, in millions	174.4				—			—			—			174.4
Diluted earnings per share	$	11.47			$	(0.11	)	$	—		$	4.98		$	16.34
Weighted-average diluted shares outstanding, in millions	175.6				—			—			—			175.6

Net earnings (from above)	$	2,015			$	(20	)	$	—		$	874		$	2,869
Other comprehensive income (loss)
Change in unamortized benefit plan costs, net of tax expense of $35	830				—			—			(874		)	(44		)
Change in cumulative translation adjustment	(4		)		—			—			—			(4		)
Other, net	2				—			—			—			2
Other comprehensive income (loss), net of tax	828				—			—			(874		)	(46		)
Comprehensive income	$	2,843			$	(20	)	$	—		$	—		$	2,823



	Year Ended December 31, 2016
	As Previously Reported			Impact of:										As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			ASU 2017-07			Accounting Change			As Adjusted
Sales
Product	$	14,738			$	342		$	—		$	—		$	15,080
Service	9,770				(144		)	—			—			9,626
Total sales	24,508				198			—			—			24,706
Operating costs and expenses
Product	11,002				286			(86		)	(5		)	11,197
Service	7,729				(68		)	(58		)	(3		)	7,600
General and administrative expenses	2,584				48			—			—			2,632
Operating income	3,193				(68		)	144			8			3,277
Other (expense) income
Interest expense	(301		)		—			—			—			(301		)
Net FAS (non-service) pension (expense) income	—				—			(141		)	752			611
Mark-to-market pension and OPB expense	—				—			—			(950		)	(950		)
Other, net	31				—			(3		)	16			44
Earnings before income taxes	2,923				(68		)	—			(174		)	2,681
Federal and foreign income tax expense (benefit)	723				(24		)	—			(61		)	638
Net earnings	$	2,200			$	(44	)	$	—		$	(113	)	$	2,043

Basic earnings per share	$	12.30			$	(0.25	)	$	—		$	(0.63	)	$	11.42
Weighted-average common shares outstanding, in millions	178.9				—			—			—			178.9
Diluted earnings per share	$	12.19			$	(0.24	)	$	—		$	(0.63	)	$	11.32
Weighted-average diluted shares outstanding, in millions	180.5				—			—			—			180.5

Net earnings (from above)	$	2,200			$	(44	)	$	—		$	(113	)	$	2,043
Other comprehensive loss
Change in unamortized benefit plan costs, net of tax expense of $20	(175		)		—			—			113			(62		)
Change in cumulative translation adjustment	(50		)		—			—			—			(50		)
Other, net	(1		)		—			—			—			(1		)
Other comprehensive loss, net of tax	(226		)		—			—			113			(113		)
Comprehensive income	$	1,974			$	(44	)	$	—		$	—		$	1,930

CONSOLIDATED STATEMENT OF FINANCIAL POSITION



	December 31, 2017
	As Previously Reported			Impact of:							As Adjusted
$ in millions					ASC Topic 606			Accounting Change
Assets
Cash and cash equivalents	$	11,225			$	—		$	—		$	11,225
Accounts receivable, net	829				225			—			1,054
Unbilled receivables, net	3,147				318			—			3,465
Inventoried costs, net	780				(382		)	—			398
Prepaid expenses and other current assets	368				77			—			445
Total current assets	16,349				238			—			16,587
Property, plant and equipment, net of accumulated depreciation of $5,066 for 2017	4,225				—			—			4,225
Goodwill	12,455				—			—			12,455
Intangible assets, net	52				—			—			52
Deferred tax assets	475				(28		)	—			447
Other non-current assets	1,361				1			—			1,362
Total assets	$	34,917			$	211		$	—		$	35,128

Liabilities
Trade accounts payable	$	1,661			$	—		—			$	1,661
Accrued employee compensation	1,382				—			—			1,382
Advance payments and amounts in excess of costs incurred	1,617				144			—			1,761
Other current liabilities	2,305				(17		)	—			2,288
Total current liabilities	6,965				127			—			7,092
Long-term debt, net of current portion of $867 for 2017	14,399				—			—			14,399
Pension and OPB plan liabilities	5,511				—			—			5,511
Other non-current liabilities	994				—			—			994
Total liabilities	27,869				127			—			27,996

Commitments and contingencies (Note 12)

Shareholders’ equity
Preferred stock, $1 par value; 10,000,000 shares authorized; no shares issued and outstanding	—				—			—			—
Common stock, $1 par value; 800,000,000 shares authorized; issued and outstanding: 2017—174,085,619	174				—			—			174
Paid-in capital	44				—			—			44
Retained earnings	11,548				84			(4,719		)	6,913
Accumulated other comprehensive (loss) income	(4,718		)		—			4,719			1
Total shareholders’ equity	7,048				84			—			7,132
Total liabilities and shareholders’ equity	$	34,917			$	211		$	—		$	35,128

CONSOLIDATED STATEMENT OF CASH FLOWS

The adoption of ASC Topic 606 and ASU 2017-07 and our Accounting change did not have an impact on our investing or financing cash flows for the years ended December 31, 2017 and 2016.



	Year Ended December 31, 2017
	As Previously Reported			Impact of:						As Adjusted
$ in millions	As Previously Reported			ASC Topic 606			Accounting Change			As Adjusted
Operating activities
Net earnings	$	2,015		$	(20	)	$	874		$	2,869
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	475			—			—			475
Mark-to-market pension and OPB benefit	—			—			(536		)	(536		)
Stock-based compensation	94			—			—			94
Deferred income taxes	603			(35		)	417			985
Changes in assets and liabilities:
Accounts receivable, net	(187		)	(22		)	—			(209		)
Unbilled receivables, net	(490		)	68			—			(422		)
Inventoried costs, net	36			(11		)	—			25
Prepaid expenses and other assets	(81		)	(11		)	—			(92		)
Accounts payable and other liabilities	539			31			—			570
Income taxes payable, net	(157		)	—			—			(157		)
Retiree benefits⁽¹⁾	(191		)	—			(755		)	(946		)
Other, net	(43		)	—			—			(43		)
Net cash provided by operating activities	$	2,613		$	—		$	—		$	2,613



	Year Ended December 31, 2016
	As Previously Reported			Impact of:						As Adjusted
$ in millions	As Previously Reported			ASC Topic 606			Accounting Change			As Adjusted
Operating activities
Net earnings	$	2,200		$	(44	)	$	(113	)	$	2,043
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	456			—			—			456
Mark-to-market pension and OPB expense	—			—			950			950
Stock-based compensation	93			—			—			93
Deferred income taxes	36			(27		)	(69		)	(60		)
Changes in assets and liabilities:
Accounts receivable, net	55			(9		)	—			46
Unbilled receivables, net	(516		)	305			—			(211		)
Inventoried costs, net	(15		)	(38		)	—			(53		)
Prepaid expenses and other assets	(110		)	(7		)	—			(117		)
Accounts payable and other liabilities	198			(180		)	—			18
Income taxes payable, net	148			—			—			148
Retiree benefits⁽¹⁾	393			—			(768		)	(375		)
Other, net	(125		)	—			—			(125		)
Net cash provided by operating activities	$	2,813		$	—		$	—		$	2,813


⁽¹⁾	Includes company contributions to our pension and OPB plans as well as net periodic benefit costs, excluding MTM pension and OPB expense, which is presented as a separate non-cash item above.

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY

The adoption of ASC Topic 606 and ASU 2017-07 and our Accounting change did not have an impact on the changes in common stock and paid-in capital for the years ended December 31, 2017 and 2016.



	Year Ended December 31, 2017
	As Previously Reported			Impact of:							As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			Accounting Change			As Adjusted
Retained earnings
Beginning of year	$	10,630			$	104		$	(5,593	)	$	5,141
Common stock repurchased	(371		)		—			—			(371		)
Net earnings	2,015				(20		)	874			2,869
Dividends declared	(687		)		—			—			(687		)
Stock compensation	(39		)		—			—			(39		)
End of year	11,548				84			(4,719		)	6,913

Accumulated other comprehensive (loss) income
Beginning of year	(5,546		)		—			5,593			47
Other comprehensive income (loss), net of tax	828				—			(874		)	(46		)
End of year	(4,718		)		—			4,719			1
Total shareholders’ equity	$	7,048			$	84		$	—		$	7,132



	Year Ended December 31, 2016
	As Previously Reported			Impact of:							As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			Accounting Change			As Adjusted
Retained earnings
Beginning of year	$	10,661			$	148		$	(5,480	)	$	5,329
Common stock repurchased	(1,548		)		—			—			(1,548		)
Net earnings	2,200				(44		)	(113		)	2,043
Dividends declared	(633		)		—			—			(633		)
Stock compensation	(50		)		—			—			(50		)
End of year	10,630				104			(5,593		)	5,141

Accumulated other comprehensive (loss) income
Beginning of year	(5,320		)		—			5,480			160
Other comprehensive income (loss), net of tax	(226		)		—			113			(113		)
End of year	(5,546		)		—			5,593			47
Total shareholders’ equity	$	5,259			$	104		$	—		$	5,363

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Principles of Consolidation

Accounting Estimates

Revenue Recognition

Contract Estimates

General and Administrative Expenses

Research and Development

Company-sponsored research and development activities primarily include efforts related to government programs.

Customer-funded research and development activities are charged directly to the related contracts.

Income Taxes

Cash and cash equivalents

Cash and Cash Equivalents

Fair Value of Financial Instruments

These two types of inputs create the following fair value hierarchy:

Level 1 - Quoted prices for identical instruments in active markets.

Level 3 - Significant inputs to the valuation model are unobservable.

We calculated the fair value of long-term debt using Level 2 inputs, based on interest rates available for debt with terms and maturities similar to the company’s existing debt arrangements.

Marketable Securities

Derivative Financial Instruments

Commodity derivatives are valued based on prices of future exchanges and recently reported transactions in the marketplace. For foreign currency forward contracts, where model-derived valuations are appropriate, the company utilizes the income approach to determine the fair value and uses the applicable London Interbank Offered Rate (LIBOR) swap rates.

Inventoried Costs

Cash Surrender Value of Life Insurance Policies

Property, Plant and Equipment



		December 31
Useful life in years, $ in millions	Useful Life	2018			2017
Land and land improvements	Up to 40⁽¹⁾	$	636		$	420
Buildings and improvements	Up to 40	2,139			1,834
Machinery and other equipment	Up to 20	6,618			5,105
Capitalized software costs	3-5	603			537
Leasehold improvements	Length of Lease⁽²⁾	1,745			1,395
Property, plant and equipment, at cost		11,741			9,291
Accumulated depreciation		(5,369		)	(5,066		)
Property, plant and equipment, net		$	6,372		$	4,225


⁽¹⁾	Land is not a depreciable asset.


⁽²⁾	Leasehold improvements are depreciated over the shorter of the useful life of the asset or the length of the lease.

Goodwill and Other Purchased Intangible Assets

The company’s other purchased intangible assets are being amortized over an aggregate weighted-average period of 12 years.

Leases

Litigation, Commitments, and Contingencies

Litigation, Commitments and Contingencies

Environmental costs

Environmental Costs

These amounts reflect a $103 million increase during 2018 in our estimated recovery of certain environmental remediation costs and are evaluated for recoverability on a routine basis.

Retirement Benefits

Change in Accounting Method

Private equities: The term of each fund is typically 10 or more years and the fund’s investors do not have an option to redeem their interest in the fund.

Opportunistic investments: Opportunistic investments are primarily held in partnerships with a 5-10 year life.

For the majority of the plans’ assets, the investment policies require that the asset allocation be maintained within the following ranges as of December 31, 2018:



		Asset Allocation Ranges
Cash and cash equivalents		0% - 12%
Global Public Equities		35% - 55%
Fixed-income securities		20% - 40%
Alternative investments		13% - 33%

Fixed-income funds: Redemption periods are daily, monthly or quarterly with various notice requirements but generally are less than 30 days.

Hedge funds: The redemption period of hedge funds is generally monthly or quarterly with various notice requirements from 30 to 95 days.

U.S. and International equities: Generally, redemption periods are daily or monthly with a notice requirement less than 30 days.

Stock Compensation

Accumulated Other Comprehensive Loss

The reclassifications are included in the computation of net periodic benefit cost. See Note 13 for further information.

Earnings Per Share

Diluted earnings per share include the dilutive effect of awards granted to employees under stock-based compensation plans.

We calculate basic earnings per share by dividing net earnings by the weighted-average number of shares of common stock outstanding during each period.

Fiscal Month Accounting Convention

It is legacy Northrop Grumman’s long-standing practice to establish actual interim closing dates using a “fiscal” calendar in which we close our books on a Friday near each quarter-end date, in order to normalize the potentially disruptive effects of quarterly closings on business processes. Similarly, Innovation Systems uses a “fiscal” calendar by closing its books on a Sunday near these quarter-end dates and will continue this practice until its business processes are aligned with legacy Northrop Grumman’s. This practice is only used at interim periods within a reporting year.

Trade and Other Accounts Receivable, Unbilled Receivables, Policy [Policy Text Block]

Accounts receivable, net represent amounts billed and due from customers.

Unbilled receivables, net represent revenue recognized under the cost-to-cost method that exceeds amounts billed to customers.

New Accounting Pronouncements, Policy

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Change in Accounting Estimate [Table Text Block]

The following table presents the effect of aggregate net EAC adjustments:



	Year Ended December 31
$ in millions, except per share data	2018		2017		2016
Operating income	$	577	$	360	$	443
Net earnings⁽¹⁾	456		234		288
Diluted earnings per share⁽¹⁾	2.61		1.33		1.60


⁽¹⁾	Based on statutory tax rates in effect for each year presented

Contract with Customer, Asset and Liability [Table Text Block]

Net contract assets (liabilities) are as follows:



$ in millions	December 31, 2018			December 31, 2017			$ Change			% Change
Unbilled receivables, net	$	5,026		$	3,465		$	1,561		45	%
Advance payments and amounts in excess of costs incurred	(1,917		)	(1,761		)	(156		)	9	%
Net contract assets (liabilities)	$	3,109		$	1,704		$	1,405		82	%

Property, Plant and Equipment

Major classes of property, plant and equipment and their useful lives are as follows:



		December 31
Useful life in years, $ in millions	Useful Life	2018			2017
Land and land improvements	Up to 40⁽¹⁾	$	636		$	420
Buildings and improvements	Up to 40	2,139			1,834
Machinery and other equipment	Up to 20	6,618			5,105
Capitalized software costs	3-5	603			537
Leasehold improvements	Length of Lease⁽²⁾	1,745			1,395
Property, plant and equipment, at cost		11,741			9,291
Accumulated depreciation		(5,369		)	(5,066		)
Property, plant and equipment, net		$	6,372		$	4,225


⁽¹⁾	Land is not a depreciable asset.


⁽²⁾	Leasehold improvements are depreciated over the shorter of the useful life of the asset or the length of the lease.

Accumulated Other Comprehensive Loss

The components of accumulated other comprehensive (loss) income are as follows:



	December 31
$ in millions	2018			2017
Unamortized prior service credit, net of tax expense of $32 for 2018 and $76 for 2017	$	98		$	133
Cumulative translation adjustment	(144		)	(136		)
Other, net	(6		)	4
Total accumulated other comprehensive (loss) income	$	(52	)	$	1

Acquisition of Orbital ATK Schedule of Finite-Lived Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Acquired Finite-Lived Intangible Assets [Line Items]

Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]

The following table presents a summary of purchased intangible assets and their related estimated useful lives:

Earnings Per Share, Share Repurchases and Dividends on Common Stock (Tables)

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Share Repurchases

The table below summarizes the company’s share repurchases to date under the authorizations described above:



Repurchase Program Authorization Date	Amount Authorized (in millions)		Total Shares Retired (in millions)	Average Price Per Share⁽¹⁾		Date Completed	Shares Repurchased (in millions)
							Shares Repurchased (in millions)
							Year Ended December 31
							2018	2017	2016
December 4, 2014	$	3,000	18.0	$	166.70	March 2016	—	—	1.4
September 16, 2015	$	4,000	11.3	$	241.66		3.8	1.6	5.9
December 4, 2018	$	3,000	—	$	—		—	—	—
							3.8	1.6	7.3


⁽¹⁾	Includes commissions paid.

Acquisition of Orbital ATK Pro Forma Financial Information (Tables)

12 Months Ended

Dec. 31, 2018

Business Combinations [Abstract]

Business Acquisition, Pro Forma Information [Table Text Block]



	Year Ended December 31
$ in millions, except per share amounts	2018		2017
Sales	$	32,319	$	30,634
Net earnings	3,417		2,938
Diluted earnings per share	19.57		16.73

Acquisition of Orbital ATK Purchase Price (Tables)

7 Months Ended

12 Months Ended

Dec. 31, 2018

Business Acquisition [Line Items]

Schedule of Business Acquisitions, by Acquisition [Table Text Block]

The Merger date fair value of the consideration transferred totaled $7.7 billion in cash, which was comprised of the following:



$ in millions, except per share amounts	Purchase price
Shares of Orbital ATK common stock outstanding as of the Merger date	57,562,152
Cash consideration per share of Orbital ATK common stock	$	134.50
Total purchase price	$	7,742

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]

The following preliminary purchase price allocation table presents the company’s refined estimate of the fair values of assets acquired and liabilities assumed at the Merger date:



$ in millions	As of June 6, 2018
Cash and cash equivalents	$	85
Accounts receivable	596
Unbilled receivables	1,264
Inventoried costs	220
Other current assets	214
Property, plant and equipment	1,509
Goodwill	6,222
Intangible assets	1,525
Other non-current assets	151
Total assets acquired	11,786
Trade accounts payable	(397		)
Accrued employee compensation	(158		)
Advance payments and amounts in excess of costs incurred	(222		)
Below market contracts⁽¹⁾	(151		)
Other current liabilities	(412		)
Long-term debt	(1,687		)
Pension and OPB plan liabilities	(613		)
Deferred tax liabilities	(248		)
Other non-current liabilities	(156		)
Total liabilities assumed	(4,044		)
Total purchase price	$	7,742


⁽¹⁾	Included in Other current liabilities in the consolidated statements of financial position.

Accounts Receivable, Net (Tables)

12 Months Ended

Dec. 31, 2018

Receivables [Abstract]

Accounts receivable

Accounts receivable consisted of the following:



	December 31
$ in millions	2018			2017
Due from U.S. government ⁽¹⁾	$	1,164		$	825
Due from international and other customers	318			268
Accounts receivable, gross	1,482			1,093
Allowance for doubtful accounts	(34		)	(39		)
Accounts receivable, net	$	1,448		$	1,054


⁽¹⁾	Includes receivables due from the U.S. government associated with foreign military sales (FMS). For FMS, we contract with and are paid by the U.S. government.

Unbilled Receivables, Net (Tables)

12 Months Ended

Dec. 31, 2018

Unbilled Receivables, Net [Abstract]

Unbilled receivables

Unbilled receivables consisted of the following:



	December 31
$ in millions	2018			2017
Due from U.S. government ⁽¹⁾
Unbilled receivables	$	16,823		$	12,513
Progress and performance-based payments received	(12,539		)	(9,447		)
Total due from U.S. government	4,284			3,066
Due from international and other customers
Unbilled receivables	3,811			3,424
Progress and performance-based payments received	(3,030		)	(2,986		)
Total due from international and other customers	781			438
Unbilled receivables, net of progress and performance-based payments received	5,065			3,504
Allowance for doubtful accounts	(39		)	(39		)
Unbilled receivables, net	$	5,026		$	3,465


⁽¹⁾	Includes unbilled receivables due from the U.S. government associated with FMS sales. For FMS, we contract with and are paid by the U.S. government.

Inventoried Costs, Net (Tables)

12 Months Ended

Dec. 31, 2018

Inventory Disclosure [Abstract]

Inventoried Costs

Inventoried costs, net consisted of the following:



	December 31
$ in millions	2018			2017
Production costs of contracts in process	$	402		$	312
G&A expenses	16			30
	418			342
Progress and performance-based payments received	(41		)	(41		)
	377			301
Product inventory and raw material	277			97
Inventoried costs, net	$	654		$	398

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Income tax expense



	Year Ended December 31
$ in millions	2018		2017		2018		2017
	Income Tax Expense				Income Tax Rate
Reduction of U.S. Corporate Income Tax Rate	$	—	$	265	—	%	6.3	%
Transition Tax on Foreign Earnings	5		13		0.1		0.3
Acceleration of Depreciation	—		5		—		0.1
Other	—		2		—		0.1
Total	$	5	$	285	0.1	%	6.8	%



	Year Ended December 31
$ in millions	2018			2017			2018		2017
	Deferred Tax Assets						Other Current Liabilities
Reduction of U.S. Corporate Income Tax Rate	$	—		$	(265	)	$	—	$	—
Transition Tax on Foreign Earnings	(5		)	(13		)	—		—
Acceleration of Depreciation	17			(80		)	17		(75		)
Other	—			—			—		2
Total	$	12		$	(358	)	$	17	$	(73	)

Federal and foreign income tax expense consisted of the following:



	Year Ended December 31
$ in millions	2018		2017			2016
Federal income tax expense:
Current	$	292	$	449		$	661
Deferred	213		907			(36		)
Total federal income tax expense	505		1,356			625
Foreign income tax expense:
Current	7		8			14
Deferred	1		(4		)	(1		)
Total foreign income tax expense	8		4			13
Total federal and foreign income tax expense	$	513	$	1,360		$	638

Income tax reconciliation

Income tax expense differs from the amount computed by multiplying earnings before income taxes by the statutory federal income tax rate due to the following:



	Year Ended December 31
$ in millions	2018					2017					2016
Income tax expense at statutory rate	$	786		21.0	%	$	1,480		35.0	%	$	938		35.0	%
Stock compensation - excess tax benefits	(27		)	(0.7	)	(48		)	(1.1	)	(85		)	(3.2	)
Research credit	(186		)	(5.0	)	(130		)	(3.1	)	(61		)	(2.2	)
Manufacturing deduction	—			—		(97		)	(2.3	)	(58		)	(2.2	)
Settlements with taxing authorities	—			—		(42		)	(1.0	)	(40		)	(1.5	)
Repatriation of non-U.S. earnings	—			—		—			—		(33		)	(1.2	)
Impacts related to the 2017 Tax Act	(84		)	(2.2	)	285			6.8		—			—
MTM benefit tax rate differential⁽¹⁾	—			—		(72		)	(1.7	)	—			—
Other, net	24			0.6		(16		)	(0.4	)	(23		)	(0.9	)
Total federal and foreign income taxes	$	513		13.7	%	$	1,360		32.2	%	$	638		23.8	%

Unrecognized tax benefit rollforward

The change in unrecognized tax benefits during 2018, 2017 and 2016, excluding interest, is as follows:



	December 31
$ in millions	2018			2017			2016
Unrecognized tax benefits at beginning of the year	$	283		$	135		$	223
Additions based on tax positions related to the current year	293			102			35
Additions for tax positions of prior years	207			110			2
Reductions for tax positions of prior years	(23		)	(44		)	(40		)
Settlements with taxing authorities	(7		)	(20		)	(84		)
Other, net	(5		)	—			(1		)
Net change in unrecognized tax benefits	465			148			(88		)
Unrecognized tax benefits at end of the year	$	748		$	283		$	135

Components of deferred tax assets and liabilities



	December 31
$ in millions	2018			2017
Deferred Tax Assets
Retiree benefits	$	1,541		$	1,477
Accrued employee compensation	308			263
Provisions for accrued liabilities	139			193
Inventory	650			447
Stock-based compensation	42			46
Tax credits	174			9
Other	59			30
Gross deferred tax assets	2,913			2,465
Less valuation allowance	(142		)	(26		)
Net deferred tax assets	2,771			2,439
Deferred Tax Liabilities
Goodwill	511			508
Purchased intangibles	346			9
Property, plant and equipment, net	518			256
Contract accounting differences	1,381			1,182
Other	29			37
Deferred tax liabilities	2,785			1,992
Total net deferred tax (liabilities) assets	$	(14	)	$	447

Goodwill and Other Purchased Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill [Table Text Block]

Changes in the carrying amounts of goodwill for the years ended December 31, 2017 and 2018, were as follows:



$ in millions	Aerospace Systems		Innovation Systems		Mission Systems			Technology Services			Total
Balance as of December 31, 2016	$	3,742	$	—	$	6,694		$	2,014		$	12,450
Other⁽¹⁾	—		—		2			3			5
Balance as of December 31, 2017	$	3,742	$	—	$	6,696		$	2,017		$	12,455
Acquisition of Orbital ATK	418		5,256		469			79			6,222
Other⁽¹⁾	—		—		(2		)	(3		)	(5		)
Balance as of December 31, 2018	$	4,160	$	5,256	$	7,163		$	2,093		$	18,672


⁽¹⁾	Other consists primarily of adjustments for foreign currency translation.

Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]

Net customer-related and other intangible assets, including the fair value of purchased intangible assets acquired in the Merger, are as follows:



	December 31
$ in millions	2018			2017
Gross customer-related and other intangible assets	$	3,356		$	1,833
Less accumulated amortization	(1,984		)	(1,781		)
Net customer-related and other intangible assets	$	1,372		$	52

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

As of December 31, 2018, the expected future amortization of purchased intangibles for each of the next five years is as follows:



$ in millions
2019	$	331
2020	262
2021	204
2022	197
2023	78

Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair value of assets and liabilities measured on a recurring basis



	December 31, 2018								December 31, 2017
$ in millions	Level 1		Level 2			Total			Level 1		Level 2		Total
Financial Assets (Liabilities)
Marketable securities	$	319	$	1		$	320		$	352	$	1	$	353
Marketable securities valued using NAV	—		—			15			—		—		—
Total marketable securities	319		1			335			352		1		353
Derivatives	—		(10		)	(10		)	—		—		—

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Long-term debt

Long-term debt consists of the following:



$ in millions		December 31
$ in millions		2018			2017
Fixed-rate notes and debentures, maturing in	Interest rate
2018	1.75%	$	—		$	850
2019	5.05%	500			500
2020	2.08%	1,000			1,000
2021	3.50%	700			700
2022	2.55%	1,500			1,500
2023	3.25%	1,050			1,050
2025	2.93%	1,500			1,500
2026	7.75% - 7.88%	527			527
2027	3.20%	750			750
2028	3.25%	2,000			2,000
2031	7.75%	466			466
2040	5.05%	300			300
2043	4.75%	950			950
2045	3.85%	600			600
2047	4.03%	2,250			2,250
Credit facilities	1.89%	108			134
Other	Various	272			271
Debt issuance costs		(73		)	(82		)
Total long-term debt		14,400			15,266
Less: current portion⁽¹⁾		517			867
Long-term debt, net of current portion		$	13,883		$	14,399

Long-term debt maturities

Maturities of long-term debt as of December 31, 2018, are as follows:



$ in millions
Year Ending December 31
2019	$	517
2020	1,127
2021	741
2022	1,505
2023	1,053
Thereafter	9,532
Total principal payments	14,475
Unamortized premium on long-term debt, net of discount	(2		)
Debt issuance costs	(73		)
Total long-term debt	$	14,400

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28541-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21538-112644

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
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-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2018

Environmental Remediation Range of Future Costs [Line Items]

Environmental Remediation [Table Text Block]



$ in millions	Range of Reasonably Possible Future Costs⁽¹⁾	Accrued Costs⁽²⁾		Deferred Costs⁽³⁾
December 31, 2018	$447 - $835	$	461	$	343
December 31, 2017	405 - 792	410		207


⁽¹⁾	Estimated remediation costs are not discounted to present value. The range of reasonably possible future costs does not take into consideration amounts expected to be recoverable through overhead charges on U.S. government contracts.


⁽²⁾	As of December 31, 2018, $159 million is recorded in Other current liabilities and $302 million is recorded in Other non-current liabilities.


⁽³⁾	As of December 31, 2018, $127 million is deferred in Prepaid expenses and other current assets and $216 million is deferred in Other non-current assets. These amounts reflect a $103 million increase during 2018 in our estimated recovery of certain environmental remediation costs and are evaluated for recoverability on a routine basis.

Schedule of Future Minimum Rental Payments for Operating Leases

Minimum rental commitments under long-term non-cancelable operating leases as of December 31, 2018 are payable as follows:



$ in millions
Year Ending December 31
2019	$	312
2020	270
2021	221
2022	186
2023	152
Thereafter	939
Total minimum lease payments	$	2,080

Retirement Benefits (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Components of net periodic benefit cost

The cost to the company of its retirement benefit plans is shown in the following table:



	Year Ended December 31
	Pension Benefits									Medical and Life Benefits
$ in millions	2018			2017			2016			2018			2017			2016
Components of net periodic benefit cost
Service cost	$	404		$	388		$	390		$	21		$	20		$	29
Interest cost	1,226			1,250			1,302			76			85			95
Expected return on plan assets	(2,217		)	(1,885		)	(1,853		)	(101		)	(89		)	(86		)
Amortization of prior service credit	(58		)	(57		)	(60		)	(21		)	(22		)	(22		)
Mark-to-market expense (benefit)	699			(445		)	1,041			(44		)	(91		)	(91		)
Other	—			(7		)	—			—			—			—
Net periodic benefit cost	$	54		$	(756	)	$	820		$	(69	)	$	(97	)	$	(75	)

Changes in unamortized benefit plan costs

The table below summarizes the components of changes in unamortized prior service credit for the years ended December 31, 2016, 2017 and 2018:



$ in millions	Pension Benefits			Medical and Life Benefits			Total
Changes in unamortized prior service credit
Amortization of prior service credit	$	60		$	22		$	82
Tax expense	(11		)	(9		)	(20		)
Change in unamortized prior service credit – 2016	49			13			62
Amortization of prior service credit	57			22			79
Tax expense	(26		)	(9		)	(35		)
Change in unamortized prior service credit – 2017	31			13			44
Amortization of prior service credit	58			21			79
Tax expense	(14		)	(5		)	(19		)
Change in unamortized prior service credit – 2018	$	44		$	16		$	60

Change in plan assets and amounts recognized in the consolidated statements of financial position



	Pension Benefits						Medical and Life Benefits
$ in millions	2018			2017			2018			2017
Plan Assets
Fair value of plan assets at beginning of year	$	27,226		$	24,384		$	1,338		$	1,208
Net (loss) gain on plan assets	(1,043		)	3,885			(65		)	208
Employer contributions	370			596			38			45
Participant contributions	9			11			25			24
Benefits paid	(1,685		)	(1,617		)	(148		)	(144		)
Acquired plan assets	2,293			—			58			—
Other	(20		)	(33		)	1			(3		)
Fair value of plan assets at end of year	27,150			27,226			1,247			1,338
Projected Benefit Obligation
Projected benefit obligation at beginning of year	31,967			30,409			2,110			2,100
Service cost	404			388			21			20
Interest cost	1,226			1,250			76			85
Participant contributions	9			11			25			24
Actuarial loss (gain)	(2,561		)	1,544			(211		)	26
Benefits paid	(1,685		)	(1,617		)	(148		)	(144		)
Acquired benefit obligation	2,895			—			50			—
Other	(24		)	(18		)	7			(1		)
Projected benefit obligation at end of year	32,231			31,967			1,930			2,110
Funded status	$	(5,081	)	$	(4,741	)	$	(683	)	$	(772	)

Classification of amounts recognized in the consolidated statements of financial position
Non-current assets	$	77		$	82		$	124		$	112
Current liability	(164		)	(154		)	(46		)	(42		)
Non-current liability	(4,994		)	(4,669		)	(761		)	(842		)

Pension plans with accumulated benefit obligations in excess of fair value of plan assets

Amounts for pension plans with accumulated benefit obligations in excess of fair value of plan assets are as follows:



	December 31
$ in millions	2018		2017
Projected benefit obligation	$	30,259	$	29,804
Accumulated benefit obligation	29,961		29,454
Fair value of plan assets	25,101		24,981

Weighted-average plan assumptions

On a weighted-average basis, the following assumptions were used to determine benefit obligations and net periodic benefit cost:



	Pension Benefits				Medical and Life Benefits
	2018		2017		2018		2017
Assumptions used to determine benefit obligation at December 31
Discount rate	4.31	%	3.68	%	4.30	%	3.66	%
Initial cash balance crediting rate assumed for the next year	3.00	%	2.75	%
Rate to which the cash balance crediting rate is assumed to increase (the ultimate rate)	3.25	%	3.00	%
Year that the cash balance crediting rate reaches the ultimate rate	2024		2023
Rate of compensation increase	3.00	%	3.00	%
Initial health care cost trend rate assumed for the next year					6.20	%	6.50	%
Rate to which the health care cost trend rate is assumed to decline (the ultimate trend rate)					5.00	%	5.00	%
Year that the health care cost trend rate reaches the ultimate trend rate					2023		2023
Assumptions used to determine benefit cost for the year ended December 31
Discount rate	3.68	%	4.19	%	3.66	%	4.13	%
Initial cash balance crediting rate assumed for the next year	2.75	%	3.10	%
Rate to which the cash balance crediting rate is assumed to increase (the ultimate rate)	3.00	%	3.60	%
Year that the cash balance crediting rate reaches the ultimate rate	2023		2022
Expected long-term return on plan assets	8.00	%	8.00	%	7.65	%	7.70	%
Rate of compensation increase	3.00	%	3.00	%
Initial health care cost trend rate assumed for the next year					6.50	%	6.50	%
Rate to which the health care cost trend rate is assumed to decline (the ultimate trend rate)					5.00	%	5.00	%
Year that the health care cost trend rate reaches the ultimate trend rate					2023		2020

Plan asset allocation

For the majority of the plans’ assets, the investment policies require that the asset allocation be maintained within the following ranges as of December 31, 2018:



		Asset Allocation Ranges
Cash and cash equivalents		0% - 12%
Global Public Equities		35% - 55%
Fixed-income securities		20% - 40%
Alternative investments		13% - 33%



	Level 1				Level 2				Level 3				Total
$ in millions	2018		2017		2018		2017		2018		2017		2018		2017
Asset category
Cash and cash equivalents	$	209	$	55	$	2,655	$	4,086					$	2,864	$	4,141
U.S. equities	2,859		3,365								$	1	2,859		3,366
International equities	2,711		2,453						$	1	1		2,712		2,454
Fixed-income securities
U.S. Treasuries	26		—		1,501		1,282						1,527		1,282
U.S. Government Agency					322		345						322		345
Non-U.S. Government					206		135						206		135
Corporate debt	34		—		4,141		4,406						4,175		4,406
Asset backed					297		255						297		255
High yield debt	11		—		153		866						164		866
Bank loans					20		248						20		248
Other Assets	15		15		51		3		2		2		68		20
Investments valued using NAV as a practical expedient
U.S. equities													1,170		1,053
International equities													4,017		4,315
Fixed-income funds													1,386		129
Hedge funds													351		166
Opportunistic investments													1,367		873
Private equities													2,510		2,091
Real estate funds													2,382		2,419
Fair value of plan assets at the end of the year	$	5,865	$	5,888	$	9,346	$	11,626	$	3	$	4	$	28,397	$	28,564

Estimated benefit payments



$ in millions	Pension Plans		Medical and Life Plans		Total
Year Ending December 31
2019	$	1,781	$	153	$	1,934
2020	1,834		155		1,989
2021	1,880		142		2,022
2022	1,928		141		2,069
2023	1,970		139		2,109
2024 through 2028	10,384		651		11,035

Stock Compensation Plans and Other Compensation Arrangements (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock Award Rollforward Activity



	Stock Awards (in thousands)		Weighted- Average Grant Date Fair Value Per Share		Weighted- Average Remaining Contractual Term (in years)
Outstanding at January 1, 2016	1,586		$	122	1.2
Granted	483		186
Vested	(872	)	97
Forfeited	(49	)	143
Outstanding at December 31, 2016	1,148		$	167	1.3
Granted	397		233
Vested	(521	)	152
Forfeited	(86	)	198
Outstanding at December 31, 2017	938		$	192	1.0
Granted	376		321
Vested	(455	)	181
Forfeited	(63	)	250
Outstanding at December 31, 2018	796		$	244	0.8

Cash Units and Cash Performance Units Aggregate Payout Amount [Table Text Block]

The following table presents the minimum and maximum aggregate payout amounts related to those cash awards granted for the periods presented:



	Year Ended December 31
$ in millions	2018		2017		2016
Minimum aggregate payout amount	$	36	$	38	$	39
Maximum aggregate payout amount	205		201		199

Segment Information (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Sales and operating income by segment

The following table presents sales and operating income by segment:



	Year Ended December 31
$ in millions	2018			2017			2016
Sales
Aerospace Systems	$	13,096		$	12,131		$	10,853
Innovation Systems	3,276			—			—
Mission Systems	11,709			11,470			11,161
Technology Services	4,297			4,687			4,765
Intersegment eliminations	(2,283		)	(2,284		)	(2,073		)
Total sales	30,095			26,004			24,706
Operating income
Aerospace Systems	1,411			1,289			1,198
Innovation Systems	343			—			—
Mission Systems	1,520			1,442			1,468
Technology Services	443			449			456
Intersegment eliminations	(270		)	(277		)	(258		)
Total segment operating income	3,447			2,903			2,864
Net FAS (service)/CAS pension adjustment	613			638			457
Unallocated corporate expense	(277		)	(319		)	(39		)
Other	(3		)	(4		)	(5		)
Total operating income	$	3,780		$	3,218		$	3,277

Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]



Sales by Customer Type	Year Ended December 31
	2018				2017				2016
$ in millions	$		%⁽³⁾		$		%⁽³⁾		$		%⁽³⁾
Aerospace Systems
U.S. Government ⁽¹⁾	$	11,380	87	%	$	10,521	87	%	$	9,277	86	%
International ⁽²⁾	1,371		10	%	1,160		10	%	1,192		11	%
Other Customers	148		1	%	155		1	%	144		1	%
Intersegment sales	197		2	%	295		2	%	240		2	%
Aerospace Systems sales	13,096		100	%	12,131		100	%	10,853		100	%
Innovation Systems
U.S. Government ⁽¹⁾	2,241		68	%	—		—		—		—
International ⁽²⁾	615		19	%	—		—		—		—
Other Customers	293		9	%	—		—		—		—
Intersegment sales	127		4	%	—		—		—		—
Innovation Systems sales	3,276		100	%	—		—		—		—
Mission Systems
U.S. Government ⁽¹⁾	8,803		75	%	8,876		77	%	8,737		78	%
International ⁽²⁾	1,647		14	%	1,540		14	%	1,416		13	%
Other Customers	114		1	%	100		1	%	133		1	%
Intersegment sales	1,145		10	%	954		8	%	875		8	%
Mission Systems sales	11,709		100	%	11,470		100	%	11,161		100	%
Technology Services
U.S. Government ⁽¹⁾	2,372		55	%	2,572		55	%	2,722		57	%
International ⁽²⁾	801		19	%	752		16	%	687		15	%
Other Customers	310		7	%	328		7	%	398		8	%
Intersegment sales	814		19	%	1,035		22	%	958		20	%
Technology Services sales	4,297		100	%	4,687		100	%	4,765		100	%
Total
U.S. Government ⁽¹⁾	24,796		82	%	21,969		85	%	20,736		84	%
International ⁽²⁾	4,434		15	%	3,452		13	%	3,295		13	%
Other Customers	865		3	%	583		2	%	675		3	%
Total Sales	$	30,095	100	%	$	26,004	100	%	$	24,706	100	%


⁽¹⁾	Sales to the U.S. government include sales from contracts for which we are the prime contractor, as well as those for which we are a subcontractor and the ultimate customer is the U.S. government. Each of the company’s segments derives substantial revenue from the U.S. government.

⁽³⁾ Percentages calculated based on total segment sales.

Reconciliation of Revenue from Segments to Consolidated [Table Text Block]



Sales by Contract Type	Year Ended December 31
	2018				2017				2016
$ in millions	$		%⁽¹⁾		$		%⁽¹⁾		$		%⁽¹⁾
Aerospace Systems
Cost-type	$	7,634	59	%	$	7,193	61	%	$	6,484	61	%
Fixed-price	5,265		41	%	4,643		39	%	4,129		39	%
Intersegment sales	197				295				240
Aerospace System sales	13,096				12,131				10,853
Innovation Systems
Cost-type	843		27	%	—		—		—		—
Fixed-price	2,306		73	%	—		—		—		—
Intersegment sales	127				—				—
Innovation System sales	3,276				—				—
Mission Systems
Cost-type	4,939		47	%	5,311		51	%	5,200		51	%
Fixed-price	5,625		53	%	5,205		49	%	5,086		49	%
Intersegment sales	1,145				954				875
Mission System sales	11,709				11,470				11,161
Technology Services
Cost-type	1,588		46	%	1,693		46	%	1,770		46	%
Fixed-price	1,895		54	%	1,959		54	%	2,037		54	%
Intersegment sales	814				1,035				958
Technology Services sales	4,297				4,687				4,765
Total
Cost-type	15,004		50	%	14,197		55	%	13,454		54	%
Fixed-price	15,091		50	%	11,807		45	%	11,252		46	%
Total Sales	$	30,095			$	26,004			$	24,706


⁽¹⁾	Percentages calculated based on external customer sales.

Revenue from External Customers by Geographic Areas [Table Text Block]



Sales by Geographic Region	Year Ended December 31
	2018				2017				2016
$ in millions	$		%⁽²⁾		$		%⁽²⁾		$		%⁽²⁾
Aerospace Systems
United States	$	11,528	89	%	$	10,676	90	%	$	9,421	89	%
Asia/Pacific	705		6	%	649		6	%	579		5	%
All other ⁽¹⁾	666		5	%	511		4	%	613		6	%
Intersegment sales	197				295				240
Aerospace Systems sales	13,096				12,131				10,853
Innovation Systems
United States	2,534		80	%	—		—		—		—
Asia/Pacific	151		5	%	—		—		—		—
All other ⁽¹⁾	464		15	%	—		—		—		—
Intersegment sales	127				—				—
Innovation Systems sales	3,276				—				—
Mission Systems
United States	8,917		85	%	8,976		86	%	8,870		86	%
Asia/Pacific	659		6	%	671		6	%	514		5	%
All other ⁽¹⁾	988		9	%	869		8	%	902		9	%
Intersegment sales	1,145				954				875
Mission Systems sales	11,709				11,470				11,161
Technology Services
United States	2,682		77	%	2,900		79	%	3,120		82	%
Asia/Pacific	151		4	%	141		4	%	119		3	%
All other ⁽¹⁾	650		19	%	611		17	%	568		15	%
Intersegment sales	814				1,035				958
Technology Services sales	4,297				4,687				4,765
Total
United States	25,661		85	%	22,552		87	%	21,411		87	%
Asia/Pacific	1,666		6	%	1,461		5	%	1,212		5	%
All other ⁽¹⁾	2,768		9	%	1,991		8	%	2,083		8	%
Total Sales	$	30,095			$	26,004			$	24,706


⁽¹⁾	All other is principally comprised of Europe and the Middle East.


⁽²⁾	Percentages calculated based on external customer sales.

Intersegment sales and operating income

The following table presents intersegment sales and operating income before eliminations:



	Year Ended December 31
$ in millions	2018					2017					2016
	Sales		Operating Income			Sales		Operating Income			Sales		Operating Income
Intersegment sales and operating income
Aerospace Systems	$	197		$	23	$	295		$	33	$	240		$	28
Innovation Systems	127			1		—			—		—			—
Mission Systems	1,145			165		954			141		875			136
Technology Services	814			81		1,035			103		958			94
Total	$	2,283		$	270	$	2,284		$	277	$	2,073		$	258

Total assets by segment

The following table presents assets by segment:



	December 31
$ in millions	2018		2017
Assets
Aerospace Systems	$	9,750	$	8,497
Innovation Systems	10,368		—
Mission Systems	11,047		10,389
Technology Services	2,957		3,014
Segment assets	34,122		21,900
Corporate assets⁽¹⁾	3,531		13,228
Total assets	$	37,653	$	35,128


⁽¹⁾	Corporate assets principally consist of cash and cash equivalents, property, plant and equipment and marketable securities.

Additional information by segment

The following table presents capital expenditures and depreciation and amortization by segment:



	Year Ended December 31
$ in millions	2018		2017		2016		2018		2017		2016
	Capital Expenditures						Depreciation and Amortization⁽¹⁾
Aerospace Systems	$	781	$	665	$	451	$	243	$	234	$	216
Innovation Systems	141		—		—		84		—		—
Mission Systems	206		164		372		134		131		140
Technology Services	18		15		6		45		40		37
Corporate	103		84		91		294		70		63
Total	$	1,249	$	928	$	920	$	800	$	475	$	456


⁽¹⁾	Beginning in 2018, corporate amounts include the amortization of other purchased intangible assets and the additional depreciation expense related to the step-up in fair value of property, plant and equipment acquired through business combinations as they are not considered part of management's evaluation of segment operating performance.

Unaudited Selected Quarterly Data (Tables)

12 Months Ended

Dec. 31, 2018

Dec. 31, 2017

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Quarterly Financial Information [Text Block]



2018
In millions, except per share amounts	1st Qtr		2nd Qtr⁽¹⁾		3rd Qtr⁽¹⁾		4th Qtr⁽¹⁾
Sales	$	6,735	$	7,119	$	8,085	$	8,156
Operating income	848		817		1,172		943
Net earnings	840		789		1,244		356

Basic earnings per share	4.82		4.52		7.15		2.07
Diluted earnings per share	4.79		4.50		7.11		2.06

Weighted-average common shares outstanding	174.3		174.5		174.1		171.8
Weighted-average diluted shares outstanding	175.4		175.4		174.9		172.6



2018 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(6		)	(6		)	(6		)	23
Net earnings	101			100			100			(394		)

Basic earnings per share	0.58			0.57			0.58			(2.29		)
Diluted earnings per share	0.58			0.57			0.57			(2.28		)



2017
In millions, except per share amounts	1st Qtr		2nd Qtr		3rd Qtr		4th Qtr
Sales	$	6,410	$	6,473	$	6,569	$	6,552
Operating income	853		864		829		672
Net earnings	770		677		750		672

Basic earnings per share	4.41		3.88		4.31		3.86
Diluted earnings per share	4.37		3.86		4.28		3.83

Weighted-average common shares outstanding	174.8		174.5		174.2		174.2
Weighted-average diluted shares outstanding	176.1		175.5		175.3		175.5



2017 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(9		)	(9		)	(8		)	(32		)
Net earnings	120			122			107			525

Basic earnings per share	0.69			0.70			0.62			3.01
Diluted earnings per share	0.68			0.70			0.61			2.99

⁽¹⁾ Selected financial data includes the operating results of Innovation Systems subsequent to the Merger date.

⁽²⁾ Table reflects the effects of the Accounting change described in Note 1 on our unaudited selected quarterly financial data.

Quarterly Financial Information [Table Text Block]



2018
In millions, except per share amounts	1st Qtr		2nd Qtr⁽¹⁾		3rd Qtr⁽¹⁾		4th Qtr⁽¹⁾
Sales	$	6,735	$	7,119	$	8,085	$	8,156
Operating income	848		817		1,172		943
Net earnings	840		789		1,244		356

Basic earnings per share	4.82		4.52		7.15		2.07
Diluted earnings per share	4.79		4.50		7.11		2.06

Weighted-average common shares outstanding	174.3		174.5		174.1		171.8
Weighted-average diluted shares outstanding	175.4		175.4		174.9		172.6



2017
In millions, except per share amounts	1st Qtr		2nd Qtr		3rd Qtr		4th Qtr
Sales	$	6,410	$	6,473	$	6,569	$	6,552
Operating income	853		864		829		672
Net earnings	770		677		750		672

Basic earnings per share	4.41		3.88		4.31		3.86
Diluted earnings per share	4.37		3.86		4.28		3.83

Weighted-average common shares outstanding	174.8		174.5		174.2		174.2
Weighted-average diluted shares outstanding	176.1		175.5		175.3		175.5

Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] | Adjustments for Change in Accounting Principle [Domain]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Quarterly Financial Information [Text Block]



2017 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(9		)	(9		)	(8		)	(32		)
Net earnings	120			122			107			525

Basic earnings per share	0.69			0.70			0.62			3.01
Diluted earnings per share	0.68			0.70			0.61			2.99

Quarterly Financial Information [Table Text Block]



2018 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(6		)	(6		)	(6		)	23
Net earnings	101			100			100			(394		)

Basic earnings per share	0.58			0.57			0.58			(2.29		)
Diluted earnings per share	0.58			0.57			0.57			(2.28		)

2018 Impact of Accounting Method Changes (Tables)

12 Months Ended

Dec. 31, 2018

Error Corrections and Prior Period Adjustments Restatement [Line Items]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]



CONSOLIDATED STATEMENT OF EARNINGS AND COMPREHENSIVE INCOME
	Year Ended December 31, 2018
$ in millions, except per share amounts	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Operating income	$	3,775		$	5		$	3,780
Other (expense) income
Interest expense	(562		)	—			(562		)
Net FAS (non-service) pension benefit	514			535			1,049
Mark-to-market pension and OPB expense	—			(655		)	(655		)
Other, net	132			(2		)	130
Earnings before income taxes	3,859			(117		)	3,742
Federal and foreign income tax expense	537			(24		)	513
Net earnings	$	3,322		$	(93	)	$	3,229
Basic earnings per share	$	19.12		$	(0.53	)	$	18.59
Diluted earnings per share	$	19.03		$	(0.54	)	$	18.49

CONSOLIDATED STATEMENT OF FINANCIAL POSITION
	December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Retained earnings	$	13,965		$	(5,897	)	$	8,068
Accumulated other comprehensive (loss) income	(5,949		)	5,897			(52		)



CONSOLIDATED STATEMENT OF CASH FLOWS
	December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Operating activities
Net earnings	$	3,322		$	(93	)	$	3,229
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	800			—			800
Mark-to-market pension and OPB expense	—			655			655
Stock-based compensation	86			—			86
Deferred income taxes	263			(29		)	234
Changes in assets and liabilities:
Accounts receivable, net	202			—			202
Unbilled receivables, net	(297		)	—			(297		)
Inventoried costs, net	(37		)	—			(37		)
Prepaid expenses and other assets	(56		)	—			(56		)
Accounts payable and other liabilities	381			—			381
Income taxes payable, net	(258		)	—			(258		)
Retiree benefits⁽¹⁾	(550		)	(533		)	(1,083		)
Other, net	(29		)	—			(29		)
Net cash provided by operating activities	$	3,827		$	—		$	3,827


⁽¹⁾	Includes company contributions to our pension and OPB plans as well as net periodic benefit costs, excluding MTM pension and OPB expense, which is presented as a separate non-cash item above.



CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS’ EQUITY
	Year ended December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Retained earnings
Beginning of year	$	11,632		$	(4,719	)	$	6,913
Impact from adoption of ASU 2018-02 and ASU 2016-01	1,064			(1,085		)	(21		)
Common stock repurchased	(1,225		)	—			(1,225		)
Net earnings	3,322			(93		)	3,229
Dividends declared	(822		)	—			(822		)
Stock compensation	(6		)	—			(6		)
End of year	13,965			(5,897		)	8,068
Accumulated other comprehensive (loss) income
Beginning of year	(4,718		)	4,719			1
Impact from adoption of ASU 2018-02 and ASU 2016-01	(1,064		)	1,085			21
Other comprehensive loss, net of tax	(167		)	93			(74		)
End of year	$	(5,949	)	$	5,897		$	(52	)

CONSOLIDATED STATEMENT OF EARNINGS AND COMPREHENSIVE INCOME



	Year Ended December 31, 2017
	As Previously Reported			Impact of:										As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			ASU 2017-07			Accounting Change			As Adjusted
Sales
Product	$	16,038			$	326		$	—		$	—		$	16,364
Service	9,765				(125		)	—			—			9,640
Total sales	25,803				201			—			—			26,004
Operating costs and expenses
Product	12,271				239			(18		)	35			12,527
Service	7,578				(42		)	(12		)	23			7,547
General and administrative expenses	2,655				57			—			—			2,712
Operating income	3,299				(53		)	30			(58		)	3,218
Other (expense) income
Interest expense	(360		)		—			—			—			(360		)
Net FAS (non-service) pension (expense) income	—				—			(44		)	743			699
Mark-to-market pension and OPB benefit	—				—			—			536			536
Other, net	110				—			14			12			136
Earnings before income taxes	3,049				(53		)	—			1,233			4,229
Federal and foreign income tax expense (benefit)	1,034				(33		)	—			359			1,360
Net earnings	$	2,015			$	(20	)	$	—		$	874		$	2,869

Basic earnings per share	$	11.55			$	(0.11	)	$	—		$	5.01		$	16.45
Weighted-average common shares outstanding, in millions	174.4				—			—			—			174.4
Diluted earnings per share	$	11.47			$	(0.11	)	$	—		$	4.98		$	16.34
Weighted-average diluted shares outstanding, in millions	175.6				—			—			—			175.6

Net earnings (from above)	$	2,015			$	(20	)	$	—		$	874		$	2,869
Other comprehensive income (loss)
Change in unamortized benefit plan costs, net of tax expense of $35	830				—			—			(874		)	(44		)
Change in cumulative translation adjustment	(4		)		—			—			—			(4		)
Other, net	2				—			—			—			2
Other comprehensive income (loss), net of tax	828				—			—			(874		)	(46		)
Comprehensive income	$	2,843			$	(20	)	$	—		$	—		$	2,823



	Year Ended December 31, 2016
	As Previously Reported			Impact of:										As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			ASU 2017-07			Accounting Change			As Adjusted
Sales
Product	$	14,738			$	342		$	—		$	—		$	15,080
Service	9,770				(144		)	—			—			9,626
Total sales	24,508				198			—			—			24,706
Operating costs and expenses
Product	11,002				286			(86		)	(5		)	11,197
Service	7,729				(68		)	(58		)	(3		)	7,600
General and administrative expenses	2,584				48			—			—			2,632
Operating income	3,193				(68		)	144			8			3,277
Other (expense) income
Interest expense	(301		)		—			—			—			(301		)
Net FAS (non-service) pension (expense) income	—				—			(141		)	752			611
Mark-to-market pension and OPB expense	—				—			—			(950		)	(950		)
Other, net	31				—			(3		)	16			44
Earnings before income taxes	2,923				(68		)	—			(174		)	2,681
Federal and foreign income tax expense (benefit)	723				(24		)	—			(61		)	638
Net earnings	$	2,200			$	(44	)	$	—		$	(113	)	$	2,043

Basic earnings per share	$	12.30			$	(0.25	)	$	—		$	(0.63	)	$	11.42
Weighted-average common shares outstanding, in millions	178.9				—			—			—			178.9
Diluted earnings per share	$	12.19			$	(0.24	)	$	—		$	(0.63	)	$	11.32
Weighted-average diluted shares outstanding, in millions	180.5				—			—			—			180.5

Net earnings (from above)	$	2,200			$	(44	)	$	—		$	(113	)	$	2,043
Other comprehensive loss
Change in unamortized benefit plan costs, net of tax expense of $20	(175		)		—			—			113			(62		)
Change in cumulative translation adjustment	(50		)		—			—			—			(50		)
Other, net	(1		)		—			—			—			(1		)
Other comprehensive loss, net of tax	(226		)		—			—			113			(113		)
Comprehensive income	$	1,974			$	(44	)	$	—		$	—		$	1,930

CONSOLIDATED STATEMENT OF FINANCIAL POSITION



	December 31, 2017
	As Previously Reported			Impact of:							As Adjusted
$ in millions					ASC Topic 606			Accounting Change
Assets
Cash and cash equivalents	$	11,225			$	—		$	—		$	11,225
Accounts receivable, net	829				225			—			1,054
Unbilled receivables, net	3,147				318			—			3,465
Inventoried costs, net	780				(382		)	—			398
Prepaid expenses and other current assets	368				77			—			445
Total current assets	16,349				238			—			16,587
Property, plant and equipment, net of accumulated depreciation of $5,066 for 2017	4,225				—			—			4,225
Goodwill	12,455				—			—			12,455
Intangible assets, net	52				—			—			52
Deferred tax assets	475				(28		)	—			447
Other non-current assets	1,361				1			—			1,362
Total assets	$	34,917			$	211		$	—		$	35,128

Liabilities
Trade accounts payable	$	1,661			$	—		—			$	1,661
Accrued employee compensation	1,382				—			—			1,382
Advance payments and amounts in excess of costs incurred	1,617				144			—			1,761
Other current liabilities	2,305				(17		)	—			2,288
Total current liabilities	6,965				127			—			7,092
Long-term debt, net of current portion of $867 for 2017	14,399				—			—			14,399
Pension and OPB plan liabilities	5,511				—			—			5,511
Other non-current liabilities	994				—			—			994
Total liabilities	27,869				127			—			27,996

Commitments and contingencies (Note 12)

Shareholders’ equity
Preferred stock, $1 par value; 10,000,000 shares authorized; no shares issued and outstanding	—				—			—			—
Common stock, $1 par value; 800,000,000 shares authorized; issued and outstanding: 2017—174,085,619	174				—			—			174
Paid-in capital	44				—			—			44
Retained earnings	11,548				84			(4,719		)	6,913
Accumulated other comprehensive (loss) income	(4,718		)		—			4,719			1
Total shareholders’ equity	7,048				84			—			7,132
Total liabilities and shareholders’ equity	$	34,917			$	211		$	—		$	35,128

CONSOLIDATED STATEMENT OF CASH FLOWS

The adoption of ASC Topic 606 and ASU 2017-07 and our Accounting change did not have an impact on our investing or financing cash flows for the years ended December 31, 2017 and 2016.



	Year Ended December 31, 2017
	As Previously Reported			Impact of:						As Adjusted
$ in millions	As Previously Reported			ASC Topic 606			Accounting Change			As Adjusted
Operating activities
Net earnings	$	2,015		$	(20	)	$	874		$	2,869
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	475			—			—			475
Mark-to-market pension and OPB benefit	—			—			(536		)	(536		)
Stock-based compensation	94			—			—			94
Deferred income taxes	603			(35		)	417			985
Changes in assets and liabilities:
Accounts receivable, net	(187		)	(22		)	—			(209		)
Unbilled receivables, net	(490		)	68			—			(422		)
Inventoried costs, net	36			(11		)	—			25
Prepaid expenses and other assets	(81		)	(11		)	—			(92		)
Accounts payable and other liabilities	539			31			—			570
Income taxes payable, net	(157		)	—			—			(157		)
Retiree benefits⁽¹⁾	(191		)	—			(755		)	(946		)
Other, net	(43		)	—			—			(43		)
Net cash provided by operating activities	$	2,613		$	—		$	—		$	2,613



	Year Ended December 31, 2016
	As Previously Reported			Impact of:						As Adjusted
$ in millions	As Previously Reported			ASC Topic 606			Accounting Change			As Adjusted
Operating activities
Net earnings	$	2,200		$	(44	)	$	(113	)	$	2,043
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	456			—			—			456
Mark-to-market pension and OPB expense	—			—			950			950
Stock-based compensation	93			—			—			93
Deferred income taxes	36			(27		)	(69		)	(60		)
Changes in assets and liabilities:
Accounts receivable, net	55			(9		)	—			46
Unbilled receivables, net	(516		)	305			—			(211		)
Inventoried costs, net	(15		)	(38		)	—			(53		)
Prepaid expenses and other assets	(110		)	(7		)	—			(117		)
Accounts payable and other liabilities	198			(180		)	—			18
Income taxes payable, net	148			—			—			148
Retiree benefits⁽¹⁾	393			—			(768		)	(375		)
Other, net	(125		)	—			—			(125		)
Net cash provided by operating activities	$	2,813		$	—		$	—		$	2,813


⁽¹⁾	Includes company contributions to our pension and OPB plans as well as net periodic benefit costs, excluding MTM pension and OPB expense, which is presented as a separate non-cash item above.

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY

The adoption of ASC Topic 606 and ASU 2017-07 and our Accounting change did not have an impact on the changes in common stock and paid-in capital for the years ended December 31, 2017 and 2016.



	Year Ended December 31, 2017
	As Previously Reported			Impact of:							As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			Accounting Change			As Adjusted
Retained earnings
Beginning of year	$	10,630			$	104		$	(5,593	)	$	5,141
Common stock repurchased	(371		)		—			—			(371		)
Net earnings	2,015				(20		)	874			2,869
Dividends declared	(687		)		—			—			(687		)
Stock compensation	(39		)		—			—			(39		)
End of year	11,548				84			(4,719		)	6,913

Accumulated other comprehensive (loss) income
Beginning of year	(5,546		)		—			5,593			47
Other comprehensive income (loss), net of tax	828				—			(874		)	(46		)
End of year	(4,718		)		—			4,719			1
Total shareholders’ equity	$	7,048			$	84		$	—		$	7,132



	Year Ended December 31, 2016
	As Previously Reported			Impact of:							As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			Accounting Change			As Adjusted
Retained earnings
Beginning of year	$	10,661			$	148		$	(5,480	)	$	5,329
Common stock repurchased	(1,548		)		—			—			(1,548		)
Net earnings	2,200				(44		)	(113		)	2,043
Dividends declared	(633		)		—			—			(633		)
Stock compensation	(50		)		—			—			(50		)
End of year	10,630				104			(5,593		)	5,141

Accumulated other comprehensive (loss) income
Beginning of year	(5,320		)		—			5,480			160
Other comprehensive income (loss), net of tax	(226		)		—			113			(113		)
End of year	(5,546		)		—			5,593			47
Total shareholders’ equity	$	5,259			$	104		$	—		$	5,363

Recast 2017 and 2016 Financial Information (Tables)

12 Months Ended

Dec. 31, 2018

Error Corrections and Prior Period Adjustments Restatement [Line Items]

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]



CONSOLIDATED STATEMENT OF EARNINGS AND COMPREHENSIVE INCOME
	Year Ended December 31, 2018
$ in millions, except per share amounts	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Operating income	$	3,775		$	5		$	3,780
Other (expense) income
Interest expense	(562		)	—			(562		)
Net FAS (non-service) pension benefit	514			535			1,049
Mark-to-market pension and OPB expense	—			(655		)	(655		)
Other, net	132			(2		)	130
Earnings before income taxes	3,859			(117		)	3,742
Federal and foreign income tax expense	537			(24		)	513
Net earnings	$	3,322		$	(93	)	$	3,229
Basic earnings per share	$	19.12		$	(0.53	)	$	18.59
Diluted earnings per share	$	19.03		$	(0.54	)	$	18.49

CONSOLIDATED STATEMENT OF FINANCIAL POSITION
	December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Retained earnings	$	13,965		$	(5,897	)	$	8,068
Accumulated other comprehensive (loss) income	(5,949		)	5,897			(52		)



CONSOLIDATED STATEMENT OF CASH FLOWS
	December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Operating activities
Net earnings	$	3,322		$	(93	)	$	3,229
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	800			—			800
Mark-to-market pension and OPB expense	—			655			655
Stock-based compensation	86			—			86
Deferred income taxes	263			(29		)	234
Changes in assets and liabilities:
Accounts receivable, net	202			—			202
Unbilled receivables, net	(297		)	—			(297		)
Inventoried costs, net	(37		)	—			(37		)
Prepaid expenses and other assets	(56		)	—			(56		)
Accounts payable and other liabilities	381			—			381
Income taxes payable, net	(258		)	—			(258		)
Retiree benefits⁽¹⁾	(550		)	(533		)	(1,083		)
Other, net	(29		)	—			(29		)
Net cash provided by operating activities	$	3,827		$	—		$	3,827


⁽¹⁾	Includes company contributions to our pension and OPB plans as well as net periodic benefit costs, excluding MTM pension and OPB expense, which is presented as a separate non-cash item above.



CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS’ EQUITY
	Year ended December 31, 2018
$ in millions	As Computed Under Previous Method			Effect of Accounting Change			As Reported Under New Method
Retained earnings
Beginning of year	$	11,632		$	(4,719	)	$	6,913
Impact from adoption of ASU 2018-02 and ASU 2016-01	1,064			(1,085		)	(21		)
Common stock repurchased	(1,225		)	—			(1,225		)
Net earnings	3,322			(93		)	3,229
Dividends declared	(822		)	—			(822		)
Stock compensation	(6		)	—			(6		)
End of year	13,965			(5,897		)	8,068
Accumulated other comprehensive (loss) income
Beginning of year	(4,718		)	4,719			1
Impact from adoption of ASU 2018-02 and ASU 2016-01	(1,064		)	1,085			21
Other comprehensive loss, net of tax	(167		)	93			(74		)
End of year	$	(5,949	)	$	5,897		$	(52	)

CONSOLIDATED STATEMENT OF EARNINGS AND COMPREHENSIVE INCOME



	Year Ended December 31, 2017
	As Previously Reported			Impact of:										As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			ASU 2017-07			Accounting Change			As Adjusted
Sales
Product	$	16,038			$	326		$	—		$	—		$	16,364
Service	9,765				(125		)	—			—			9,640
Total sales	25,803				201			—			—			26,004
Operating costs and expenses
Product	12,271				239			(18		)	35			12,527
Service	7,578				(42		)	(12		)	23			7,547
General and administrative expenses	2,655				57			—			—			2,712
Operating income	3,299				(53		)	30			(58		)	3,218
Other (expense) income
Interest expense	(360		)		—			—			—			(360		)
Net FAS (non-service) pension (expense) income	—				—			(44		)	743			699
Mark-to-market pension and OPB benefit	—				—			—			536			536
Other, net	110				—			14			12			136
Earnings before income taxes	3,049				(53		)	—			1,233			4,229
Federal and foreign income tax expense (benefit)	1,034				(33		)	—			359			1,360
Net earnings	$	2,015			$	(20	)	$	—		$	874		$	2,869

Basic earnings per share	$	11.55			$	(0.11	)	$	—		$	5.01		$	16.45
Weighted-average common shares outstanding, in millions	174.4				—			—			—			174.4
Diluted earnings per share	$	11.47			$	(0.11	)	$	—		$	4.98		$	16.34
Weighted-average diluted shares outstanding, in millions	175.6				—			—			—			175.6

Net earnings (from above)	$	2,015			$	(20	)	$	—		$	874		$	2,869
Other comprehensive income (loss)
Change in unamortized benefit plan costs, net of tax expense of $35	830				—			—			(874		)	(44		)
Change in cumulative translation adjustment	(4		)		—			—			—			(4		)
Other, net	2				—			—			—			2
Other comprehensive income (loss), net of tax	828				—			—			(874		)	(46		)
Comprehensive income	$	2,843			$	(20	)	$	—		$	—		$	2,823



	Year Ended December 31, 2016
	As Previously Reported			Impact of:										As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			ASU 2017-07			Accounting Change			As Adjusted
Sales
Product	$	14,738			$	342		$	—		$	—		$	15,080
Service	9,770				(144		)	—			—			9,626
Total sales	24,508				198			—			—			24,706
Operating costs and expenses
Product	11,002				286			(86		)	(5		)	11,197
Service	7,729				(68		)	(58		)	(3		)	7,600
General and administrative expenses	2,584				48			—			—			2,632
Operating income	3,193				(68		)	144			8			3,277
Other (expense) income
Interest expense	(301		)		—			—			—			(301		)
Net FAS (non-service) pension (expense) income	—				—			(141		)	752			611
Mark-to-market pension and OPB expense	—				—			—			(950		)	(950		)
Other, net	31				—			(3		)	16			44
Earnings before income taxes	2,923				(68		)	—			(174		)	2,681
Federal and foreign income tax expense (benefit)	723				(24		)	—			(61		)	638
Net earnings	$	2,200			$	(44	)	$	—		$	(113	)	$	2,043

Basic earnings per share	$	12.30			$	(0.25	)	$	—		$	(0.63	)	$	11.42
Weighted-average common shares outstanding, in millions	178.9				—			—			—			178.9
Diluted earnings per share	$	12.19			$	(0.24	)	$	—		$	(0.63	)	$	11.32
Weighted-average diluted shares outstanding, in millions	180.5				—			—			—			180.5

Net earnings (from above)	$	2,200			$	(44	)	$	—		$	(113	)	$	2,043
Other comprehensive loss
Change in unamortized benefit plan costs, net of tax expense of $20	(175		)		—			—			113			(62		)
Change in cumulative translation adjustment	(50		)		—			—			—			(50		)
Other, net	(1		)		—			—			—			(1		)
Other comprehensive loss, net of tax	(226		)		—			—			113			(113		)
Comprehensive income	$	1,974			$	(44	)	$	—		$	—		$	1,930

CONSOLIDATED STATEMENT OF FINANCIAL POSITION



	December 31, 2017
	As Previously Reported			Impact of:							As Adjusted
$ in millions					ASC Topic 606			Accounting Change
Assets
Cash and cash equivalents	$	11,225			$	—		$	—		$	11,225
Accounts receivable, net	829				225			—			1,054
Unbilled receivables, net	3,147				318			—			3,465
Inventoried costs, net	780				(382		)	—			398
Prepaid expenses and other current assets	368				77			—			445
Total current assets	16,349				238			—			16,587
Property, plant and equipment, net of accumulated depreciation of $5,066 for 2017	4,225				—			—			4,225
Goodwill	12,455				—			—			12,455
Intangible assets, net	52				—			—			52
Deferred tax assets	475				(28		)	—			447
Other non-current assets	1,361				1			—			1,362
Total assets	$	34,917			$	211		$	—		$	35,128

Liabilities
Trade accounts payable	$	1,661			$	—		—			$	1,661
Accrued employee compensation	1,382				—			—			1,382
Advance payments and amounts in excess of costs incurred	1,617				144			—			1,761
Other current liabilities	2,305				(17		)	—			2,288
Total current liabilities	6,965				127			—			7,092
Long-term debt, net of current portion of $867 for 2017	14,399				—			—			14,399
Pension and OPB plan liabilities	5,511				—			—			5,511
Other non-current liabilities	994				—			—			994
Total liabilities	27,869				127			—			27,996

Commitments and contingencies (Note 12)

Shareholders’ equity
Preferred stock, $1 par value; 10,000,000 shares authorized; no shares issued and outstanding	—				—			—			—
Common stock, $1 par value; 800,000,000 shares authorized; issued and outstanding: 2017—174,085,619	174				—			—			174
Paid-in capital	44				—			—			44
Retained earnings	11,548				84			(4,719		)	6,913
Accumulated other comprehensive (loss) income	(4,718		)		—			4,719			1
Total shareholders’ equity	7,048				84			—			7,132
Total liabilities and shareholders’ equity	$	34,917			$	211		$	—		$	35,128

CONSOLIDATED STATEMENT OF CASH FLOWS

The adoption of ASC Topic 606 and ASU 2017-07 and our Accounting change did not have an impact on our investing or financing cash flows for the years ended December 31, 2017 and 2016.



	Year Ended December 31, 2017
	As Previously Reported			Impact of:						As Adjusted
$ in millions	As Previously Reported			ASC Topic 606			Accounting Change			As Adjusted
Operating activities
Net earnings	$	2,015		$	(20	)	$	874		$	2,869
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	475			—			—			475
Mark-to-market pension and OPB benefit	—			—			(536		)	(536		)
Stock-based compensation	94			—			—			94
Deferred income taxes	603			(35		)	417			985
Changes in assets and liabilities:
Accounts receivable, net	(187		)	(22		)	—			(209		)
Unbilled receivables, net	(490		)	68			—			(422		)
Inventoried costs, net	36			(11		)	—			25
Prepaid expenses and other assets	(81		)	(11		)	—			(92		)
Accounts payable and other liabilities	539			31			—			570
Income taxes payable, net	(157		)	—			—			(157		)
Retiree benefits⁽¹⁾	(191		)	—			(755		)	(946		)
Other, net	(43		)	—			—			(43		)
Net cash provided by operating activities	$	2,613		$	—		$	—		$	2,613



	Year Ended December 31, 2016
	As Previously Reported			Impact of:						As Adjusted
$ in millions	As Previously Reported			ASC Topic 606			Accounting Change			As Adjusted
Operating activities
Net earnings	$	2,200		$	(44	)	$	(113	)	$	2,043
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	456			—			—			456
Mark-to-market pension and OPB expense	—			—			950			950
Stock-based compensation	93			—			—			93
Deferred income taxes	36			(27		)	(69		)	(60		)
Changes in assets and liabilities:
Accounts receivable, net	55			(9		)	—			46
Unbilled receivables, net	(516		)	305			—			(211		)
Inventoried costs, net	(15		)	(38		)	—			(53		)
Prepaid expenses and other assets	(110		)	(7		)	—			(117		)
Accounts payable and other liabilities	198			(180		)	—			18
Income taxes payable, net	148			—			—			148
Retiree benefits⁽¹⁾	393			—			(768		)	(375		)
Other, net	(125		)	—			—			(125		)
Net cash provided by operating activities	$	2,813		$	—		$	—		$	2,813


⁽¹⁾	Includes company contributions to our pension and OPB plans as well as net periodic benefit costs, excluding MTM pension and OPB expense, which is presented as a separate non-cash item above.

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY

The adoption of ASC Topic 606 and ASU 2017-07 and our Accounting change did not have an impact on the changes in common stock and paid-in capital for the years ended December 31, 2017 and 2016.



	Year Ended December 31, 2017
	As Previously Reported			Impact of:							As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			Accounting Change			As Adjusted
Retained earnings
Beginning of year	$	10,630			$	104		$	(5,593	)	$	5,141
Common stock repurchased	(371		)		—			—			(371		)
Net earnings	2,015				(20		)	874			2,869
Dividends declared	(687		)		—			—			(687		)
Stock compensation	(39		)		—			—			(39		)
End of year	11,548				84			(4,719		)	6,913

Accumulated other comprehensive (loss) income
Beginning of year	(5,546		)		—			5,593			47
Other comprehensive income (loss), net of tax	828				—			(874		)	(46		)
End of year	(4,718		)		—			4,719			1
Total shareholders’ equity	$	7,048			$	84		$	—		$	7,132



	Year Ended December 31, 2016
	As Previously Reported			Impact of:							As Adjusted
$ in millions, except per share amounts	As Previously Reported				ASC Topic 606			Accounting Change			As Adjusted
Retained earnings
Beginning of year	$	10,661			$	148		$	(5,480	)	$	5,329
Common stock repurchased	(1,548		)		—			—			(1,548		)
Net earnings	2,200				(44		)	(113		)	2,043
Dividends declared	(633		)		—			—			(633		)
Stock compensation	(50		)		—			—			(50		)
End of year	10,630				104			(5,593		)	5,141

Accumulated other comprehensive (loss) income
Beginning of year	(5,320		)		—			5,480			160
Other comprehensive income (loss), net of tax	(226		)		—			113			(113		)
End of year	(5,546		)		—			5,593			47
Total shareholders’ equity	$	5,259			$	104		$	—		$	5,363

Summary of Significant Accounting Policies (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jan. 01, 2016
Summary of Significant Accounting Policies (Amounts in paragraphs)
Research and development expenses	$ 764	$ 639	$ 705
Research and Development as a Percent of Sales	2.50%	2.50%	2.90%
Cash surrender value of life insurance	$ 316	$ 340
Stock plans, vesting period	3 years
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 5,500
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit, Tax [Member] [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					3,500
Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 148
Accounting Standards Update 2018-02 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 25
Accounting Standards Update 2016-01 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 4
Liabilities, Total [Member] \| Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 1,400
Assets, Total [Member] \| Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 1,400

Summary of Significant Accounting Policies (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment
Property, plant and equipment, at cost	$ 11,741	$ 9,291
Accumulated depreciation	(5,369)	(5,066)
Property, plant, and equipment, net	6,372	4,225
Land and land improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	636	420
Buildings and improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	2,139	1,834
Machinery and other equipment
Property, Plant and Equipment
Property, plant and equipment, at cost	6,618	5,105
Capitalized software costs
Property, Plant and Equipment
Property, plant and equipment, at cost	603	537
Leasehold improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	$ 1,745	$ 1,395
Minimum \| Capitalized software costs
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	3 years
Maximum \| Land and land improvements
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	40 years
Maximum \| Buildings and improvements
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	40 years
Maximum \| Machinery and other equipment
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	20 years
Maximum \| Capitalized software costs
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	5 years

Summary of Significant Accounting Policies (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Loss
Unamortized prior service credit, net of tax expense of $32 for 2018 and $76 for 2017	$ 98	$ 133
Cumulative translation adjustment	(144)	(136)
Other, net	(6)	4
Total accumulated other comprehensive loss	(52)	1
Unamortized benefit plan costs - Tax Benefit	32	76
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	$ 60	$ 44	$ 62

Summary of Significant Accounting Policies (Details 4) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in Accounting Estimate [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period									$ 631	$ 374	$ 463
Operating income	$ 943	$ 1,172	$ 817	$ 848	$ 672	$ 829	$ 864	$ 853	3,780	3,218	3,277
Net earnings	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Diluted earnings per share	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating income									$ 577	$ 360	$ 443
Net earnings									$ 456	$ 234	$ 288
Diluted earnings per share									$ 2.61	$ 1.33	$ 1.60
Aerospace Systems [Member] \| Contracts Accounted for under Percentage of Completion [Member]
Change in Accounting Estimate [Line Items]
Operating income			$ 69			$ 56

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 55
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-Subparagraph (SX 210.7-04(19))
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+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 5) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 53,500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Explanation	We expect to recognize approximately 50 percent and 75 percent of our December 31, 2018 backlog as revenue over the next 12 and 24 months, respectively, with the remainder to be recognized thereafter.
Innovation Systems Net contract assets (liabilities)	$ 1,000
Unbilled Receivables, Current	5,026	$ 3,465
Amount of increase (decrease) in Unbilled Receivables	$ 1,561
Percent increase (decrease) in Unbilled Receivables	45.00%
Contract with Customer, Liability, Current	$ 1,917	1,761
Amount of decrease (increase) in Contract with Customer, Liability, Current	$ (156)
Percent decrease (increase) in Contract with Customer, Liability, Current	9.00%
Contract with Customer, Asset, Net, Current	$ 3,109	1,704
Amount of increase (decrease) in net contract assets (liabilities)	$ 1,405
Percent increase (decrease) in net contract assets (liabilities)	82.00%
Contract with Customer, Liability, Revenue Recognized	$ 1,300	$ 1,200	$ 1,300

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 6) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jan. 01, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income	$ 943	$ 1,172	$ 817	$ 848	$ 672	$ 829	$ 864	$ 853	$ 3,780	$ 3,218	$ 3,277
Net earnings	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Basic earnings per share	$ 2.07	$ 7.15	$ 4.52	$ 4.82	$ 3.86	$ 4.31	$ 3.88	$ 4.41	$ 18.59	$ 16.45	$ 11.42
Diluted earnings per share	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Adjustments for New Accounting Pronouncement [Member] \| Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption												$ 4
Adjustments for New Accounting Pronouncement [Member] \| Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption													$ 148
Operating income										$ (53)	$ (68)
Net earnings										$ (20)	$ (44)
Basic earnings per share										$ (0.11)	$ (0.25)
Diluted earnings per share										$ (0.11)	$ (0.24)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
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-Name Accounting Standards Codification
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-Subparagraph (d)
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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Earnings Per Share, Share Repurchases and Dividends on Common Stock (Details 1) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended				33 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 04, 2018	Sep. 16, 2015	Dec. 04, 2014
Stock Repurchase [Line Items]
Shares Repurchased	3.8	1.6	7.3
December 2014 Share Repurchase Original Authorization
Stock Repurchase [Line Items]
Amount Authorized								$ 3,000
Total Shares Retired				18.0
Average Price Per Share				$ 166.70
Shares Repurchased	0.0	0.0	1.4
September 2015 Share Repurchase Original Authorization
Stock Repurchase [Line Items]
Amount Authorized							$ 4,000
Total Shares Retired					11.3
Average Price Per Share					$ 241.66
Shares Repurchased	3.8	1.6	5.9
Amount repurchased					$ 2,700
Amount remaining under authorization for share repurchases	$ 1,300				$ 1,300
December 2018 Share Repurchase Program Original Authorization
Stock Repurchase [Line Items]
Amount Authorized						$ 3,000
Total Shares Retired	0.0
Average Price Per Share	$ 0.00
Shares Repurchased	0.0	0.0	0.0

Earnings Per Share, Share Repurchases and Dividends on Common Stock (Details 2) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended					2 Months Ended		12 Months Ended			33 Months Ended
	Jan. 04, 2019	May 31, 2018	Jan. 31, 2018	May 30, 2017	May 31, 2016	May 31, 2015	Jan. 04, 2019	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Oct. 29, 2018	Sep. 16, 2015
Equity, Class of Treasury Stock [Line Items]
Accelerated Share Repurchase								$ 1,000
Accelerated Share Repurchases, Payment													$ 1,000
Accelerated Share Repurchase Initial Receipt of Shares													3.0
Accelerated Share Repurchase Initial Receipt Monetary													$ 800
Earnings Per Share, Basic and Diluted [Abstract]
Dilutive effect of stock options and other stock awards granted									0.9	1.2	1.6
Increase (Decrease) in Stock Dividend, Percentage		9.00%	10.00%	11.00%	13.00%
Common stock dividend (in dollars per share)		$ 1.20	$ 1.10	$ 1.00	$ 0.90	$ 0.80			$ 4.70	$ 3.90	$ 3.50
Accelerated Share Repurchase Settlement, subsequent event
Equity, Class of Treasury Stock [Line Items]
Accelerated Share Repurchase Final Receipt Monetary	$ 200						$ 200
Accelerated Share Repurchase Final Receipt Shares	0.9						0.9
Accelerated Share Repurchases, Final Price Paid Per Share							$ 260.32
September 2015 Share Repurchase Original Authorization [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Value, Acquired, Par Value Method												$ 2,700
Earnings Per Share, Basic and Diluted [Abstract]
Stock Repurchase Program, Authorized Amount														$ 4,000
September 2015 Share Repurchase Original Authorization [Member] \| Accelerated Share Repurchase Settlement, subsequent event
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Value, Acquired, Par Value Method	$ 200

Acquisition of Orbital ATK (Details 1) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Revenues	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Operating Income (Loss)	943	1,172	817	848	672	829	864	853	3,780	3,218	3,277
Net earnings	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	3,229	2,869	2,043
Business Combination, Acquisition Related Costs									29
Operating Segments [Member]
Business Acquisition [Line Items]
Operating Income (Loss)									3,447	2,903	2,864
Innovation Systems \| Operating Segments [Member]
Business Acquisition [Line Items]
Revenues									3,276	0	0
Operating Income (Loss)									343	$ 0	$ 0
Net earnings									$ 273

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Acquisition of Orbital ATK Acquisition of Orbital ATK (Details 2) - USD ($) $ in Millions	6 Months Ended
	Dec. 31, 2018	Jun. 06, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 18,672		$ 12,455	$ 12,450
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles	220
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other current liabilities	114
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Pension and other post-retirement benefit plan liabilities	56
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill	$ 73
Orbital ATK [Member]
Business Acquisition [Line Items]
Goodwill		$ 6,222

Acquisition of Orbital ATK Acquisition of Orbital ATK (Details 3) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Jun. 06, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Shares, Outstanding	57,562,152
Business Acquisition, Share Price	$ 134.50
Business Combination, Consideration Transferred	$ 7,742
Goodwill		$ 18,672	$ 12,455	$ 12,450
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		12 years
Business Combination, Below Market Contracts, reduction in sales for 2018	64
Business Combination, Below Market Contracts, reduction in sales for 2019	45
Business Combination, Below Market Contracts, reduction in sales for 2020	2
Orbital ATK [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	85
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	596
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Unbilled Receivables	1,264
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	220
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets	214
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	1,509
Goodwill	6,222
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	1,525
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	151
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	11,786
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	397
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Employee-related liabilities	158
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Customer Advances	222
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Below Market Contracts	151
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other	412
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	1,687
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, NonCurrent Liabilities, Defined Benefit Plan Liability	613
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities	248
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	156
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	4,044
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	7,742
Customer Relationships [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 280
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years
Customer Contracts [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 1,245
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years

Acquisition of Orbital ATK Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Combinations [Abstract]
Pro Forma Adjustments, Orbital ATK ASC606 Sales adjustment		$ 21
Pro Forma Adjustments, Orbital ATK ASC606 Cost of Sales adjustment		21
Business Acquisition, Pro Forma Revenue	$ 32,319	30,634
Business Acquisition, Pro Forma Net Income (Loss)	$ 3,417	$ 2,938
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 19.57	$ 16.73
Pro Forma Adjustments, Orbital ATK intercompany sales elimination	$ 80	$ 155
Pro Forma Adjustments, Elimination of nonrecurring transaction costs	71	57
Pro Forma Adjustments, Additional depreciation expense, net of removal of historical depreciation	8	40
Pro Forma Adjustments, Additional interest expense due to debt issued to finance merger		208
Pro Forma Adjustments, Additional amortization expense, net of removal of historical amortization expense	90	290
Pro Forma Adjustments, Elimination of Orbital ATK’s historical amortization of net actuarial losses and prior service credits and revised pension and other post-retirement costs	51	110
Income Tax Effects of Pro Forma Adjustments	$ (5)	$ 130

Accounts Receivable, Net (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Net [Abstract]
Accounts receivable, gross	$ 1,482	$ 1,093
Allowance for doubtful accounts	(34)	(39)
Accounts receivable, net	1,448	1,054
US Government [Member]
Accounts Receivable, Net [Abstract]
Accounts receivable, gross	1,164	825
International and Other Customers [Member]
Accounts Receivable, Net [Abstract]
Accounts receivable, gross	$ 318	$ 268

Unbilled Receivables, Net (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivable, net of progress and performance-based payments received	$ 5,065	$ 3,504
Allowance for doubtful accounts	(39)	(39)
Unbilled receivables, net	5,026	3,465
US Government [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	16,823	12,513
Progress and performance-based payments received	(12,539)	(9,447)
Unbilled receivable, net of progress and performance-based payments received	4,284	3,066
International and Other Customers [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	3,811	3,424
Progress and performance-based payments received	(3,030)	(2,986)
Unbilled receivable, net of progress and performance-based payments received	$ 781	$ 438

Inventoried Costs, Net (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Production costs of contracts in process	$ 402	$ 312
General and administrative expenses	16	30
Inventoried costs	418	342
Progress and performance-based payments received	(41)	(41)
Inventoried costs, net of progress payments	377	301
Product inventory	277	97
Inventory, Net	$ 654	$ 398

Income Taxes (Details 1) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Details 1) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes on Continuing Operations (Table Amounts)
Current federal income tax expense (benefit)	$ 292	$ 449	$ 661
Deferred federal income tax expense (benefit)	213	907	(36)
Total federal income tax expense (benefit)	505	1,356	625
Current foreign income tax expense (benefit)	7	8	14
Deferred foreign income tax expense (benefit)	1	(4)	(1)
Total foreign income tax expense (benefit)	8	4	13
Total federal and foreign income tax expense	$ 513	$ 1,360	$ 638

Income Taxes (Details 2) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%	35.00%
Increase in Research Tax Credit	$ 56	$ 69
Increase in Qualified Production Activity		39
Income taxes paid, net	270	517	$ 691
Income Tax Reconciliation (Table Amounts) [Abstract]
Income tax expense at statutory rate	786	1,480	938
Stock compensation - excess tax benefits	$ (27)	$ (48)	$ (85)
Stock compensation - excess tax benefits, Percent	(0.70%)	(1.10%)	(3.20%)
Research credit	$ (186)	$ (130)	$ (61)
Research credit, Percent	(5.00%)	(3.10%)	(2.20%)
Manufacturing deduction	$ 0	$ (97)	$ (58)
Manufacturing deduction, Percent	(0.00%)	(2.30%)	(2.20%)
Settlements with taxing authorities	$ 0	$ (42)	$ (40)
Settlements with taxing authorities, Percent	0.00%	(1.00%)	(1.50%)
Repatriation of non-U.S. earnings	$ 0	$ 0	$ (33)
Repatriation of non-U.S. earnings, Percent	0.00%	0.00%	(1.20%)
Impacts related to the 2017 Tax Act	$ (84)	$ 285	$ 0
Impacts related to the 2017 Tax Act, Percent	(2.20%)	6.80%	0.00%
Effective Tax Rate Reconciliation, Mark-to-Market benefit tax rate differential, amount	$ 0	$ (72)	$ 0
Effective Tax Rate Reconciliation, Mark-to-Market benefit tax rate differential, percent	0.00%	(1.70%)	0.00%
Other, net	$ 24	$ (16)	$ (23)
Other net, Percent	0.60%	(0.40%)	(0.90%)
Total federal and foreign income tax expense	$ 513	$ 1,360	$ 638
Effective income tax rate	13.70%	32.20%	23.80%

Income Taxes (Details 3) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Details 3) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrecognized Tax Benefits Rollforward (Table Amounts) [Abstract]
Unrecognized tax benefits at beginning of the year	$ 283	$ 135	$ 223
Additions based on tax positions related to the current year	293	102	35
Additions for tax positions of prior years	207	110	2
Reductions for tax positions of prior years	(23)	(44)	(40)
Settlements with taxing authorities	(7)	(20)	(84)
Other, net	(5)	0	(1)
Net change in unrecognized tax benefits	465	148	(88)
Unrecognized tax benefits at end of the year	$ 748	$ 283	$ 135

Income Taxes (Details 4) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets (Table Amounts)
Retiree benefits	$ 1,541	$ 1,477
Accrued employee compensation	308	263
Provisions for accrued liabilities	139	193
Inventory	650	447
Stock-based compensation	42	46
Deferred Tax Assets, Tax Credit Carryforwards	174	9
Other	59	30
Gross deferred tax assets	2,913	2,465
Less valuation allowance	(142)	(26)
Net deferred tax assets	2,771	2,439
Deferred Tax Liabilities (Table Amounts)
Goodwill	511	508
Deferred Tax Liabilities, Purchase Intangibles	346	9
Property, plant and equipment, net	518	256
Contract accounting differences	1,381	1,182
Other	29	37
Gross deferred tax liabilities	2,785	1,992
Deferred Tax Liabilities, Net	$ (14)
Total net deferred tax assets		$ 447

Income Taxes (Details 5) $ in Millions	7 Months Ended	12 Months Ended
Income Taxes (Details 5) $ in Millions	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Income Tax Contingency [Line Items]
Increase in Unrecognized Tax Benefits is Reasonably Possible	$ 70	$ 70
Unrecognized Tax Benefits, Increase Resulting from Acquisition	160
Unrecognized Tax Benefits, Increase Resulting from 2017 Tax Act		100
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	24	24
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	430	430
Tax Credit Carryforward, Amount	255	255
Operating Loss Carryforwards	330	330
Tax Credit Carryforward, Valuation Allowance	110	110
Operating Loss Carryforwards, Valuation Allowance	$ 27	$ 27

Income Taxes (Details 6) - USD ($) $ in Millions	12 Months Ended
Income Taxes (Details 6) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Effective Income Tax Reconciliation, change in enacted tax rate due to 2017 Tax Act, amount	$ 5	$ 285
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%	35.00%
Impacts related to the 2017 Tax Act, Percent	0.10%	6.80%
Change in Deferred Tax Assets due to 2017 Tax Act	$ 12	$ (358)
Change in Other Current Liabilities due to 2017 Tax Act	17	(73)
Reduction in Taxes [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Reconciliation, change in enacted tax rate due to 2017 Tax Act, amount	$ 0	$ 265
Impacts related to the 2017 Tax Act, Percent	0.00%	6.30%
Change in Deferred Tax Assets due to 2017 Tax Act	$ 0	$ (265)
Change in Other Current Liabilities due to 2017 Tax Act	0	0
Transition tax on Foreign Earnings [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Reconciliation, change in enacted tax rate due to 2017 Tax Act, amount	$ 5	$ 13
Impacts related to the 2017 Tax Act, Percent	0.10%	0.30%
Change in Deferred Tax Assets due to 2017 Tax Act	$ (5)	$ (13)
Change in Other Current Liabilities due to 2017 Tax Act	0	0
Accelerated Depreciation [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Reconciliation, change in enacted tax rate due to 2017 Tax Act, amount	$ 0	$ 5
Impacts related to the 2017 Tax Act, Percent	0.00%	0.10%
Change in Deferred Tax Assets due to 2017 Tax Act	$ 17	$ (80)
Change in Other Current Liabilities due to 2017 Tax Act	17	(75)
2017 Tax Act, Other [Domain]
Income Tax Contingency [Line Items]
Effective Income Tax Reconciliation, change in enacted tax rate due to 2017 Tax Act, amount	$ 0	$ 2
Impacts related to the 2017 Tax Act, Percent	0.00%	0.10%
Change in Deferred Tax Assets due to 2017 Tax Act	$ 0	$ 0
Change in Other Current Liabilities due to 2017 Tax Act	$ 0	$ 2

Goodwill and Other Purchased Intangible Assets (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill (Table Amounts)
Beginning balance	$ 12,455	$ 12,450
Acquisition of Orbital ATK	6,222
Other	(5)	5
Ending balance	18,672	12,455
Aerospace Systems
Goodwill (Table Amounts)
Beginning balance	3,742	3,742
Acquisition of Orbital ATK	418
Other	0	0
Ending balance	4,160	3,742
Innovation Systems
Goodwill (Table Amounts)
Beginning balance	0	0
Acquisition of Orbital ATK	5,256
Other	0	0
Ending balance	5,256	0
Mission Systems
Goodwill (Table Amounts)
Beginning balance	6,696	6,694
Acquisition of Orbital ATK	469
Other	(2)	2
Ending balance	7,163	6,696
Technology Services
Goodwill (Table Amounts)
Beginning balance	2,017	2,014
Acquisition of Orbital ATK	79
Other	(3)	3
Ending balance	$ 2,093	$ 2,017

Goodwill and Other Purchased Intangible Assets (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross customer-related and other intangible assets	$ 3,356	$ 1,833
Less accumulated amortization	(1,984)	(1,781)
Net contract, program and other intangible assets	$ 1,372	$ 52

Goodwill and Other Purchased Intangible Assets (Details 3) $ in Millions	Dec. 31, 2018 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2019	$ 331
2020	262
2021	204
2022	197
2023	$ 78

Goodwill and Other Purchased Intangible Assets Goodwill and Other Purchased Intangible Assets (Details 4) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Amortization of Intangible Assets	$ 203	$ 14	$ 16
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years
Aerospace Systems [Member]
Goodwill [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss	$ 570	$ 570

Fair Value of Financial Instruments (Details 1) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	$ 335	$ 353
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	319	352
Derivative Assets (Liabilities), at Fair Value, Net	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	1	1
Debt Securities, Trading, and Equity Securities, FV-NI	0	0
Derivative Assets (Liabilities), at Fair Value, Net	(10)	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	320	353
Derivative Assets (Liabilities), at Fair Value, Net	(10)	0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	319	352
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	1	1
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	15	0
Fair Value, Measurements, Nonrecurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities	$ 0	$ 0

Fair Value of Financial Instruments (Details 2) lb in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) lb	Dec. 31, 2017 USD ($)
Foreign Exchange Forward [Member]
Derivative Instruments and Hedging Activities
Derivatives, notional amount \| $	$ 114	$ 89
Foreign Exchange Forward [Member] \| Cash Flow Hedges
Derivative Instruments and Hedging Activities
Derivatives, notional amount \| $	$ 0	$ 8
Copper [Member]
Financial Assets (Liabilities)
Derivative, Nonmonetary Notional Amount, Mass \| lb	10
Zinc [Member]
Financial Assets (Liabilities)
Derivative, Nonmonetary Notional Amount, Mass \| lb	4

Long-Term Debt (Details 1) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Long-Term Debt (Table Amounts) [Abstract]
Long-term debt	$ 14,400
Other long-term debt	272	$ 271
Debt issuance costs	(73)	(82)
Total long-term debt	14,400	15,266
Less: current portion	517	867
Long-term Debt and Capital Lease Obligations	$ 13,883	14,399
2018
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	1.75%
Long-term debt	$ 0	850
2019
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	5.05%
Long-term debt	$ 500	500
2020
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.08%
Long-term debt	$ 1,000	1,000
2021
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Long-term debt	$ 700	700
2022
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.55%
Long-term debt	$ 1,500	1,500
2023
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Long-term debt	$ 1,050	1,050
2025
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.93%
Long-term debt	$ 1,500	1,500
2026
Long-Term Debt (Table Amounts) [Abstract]
Long-term debt	$ 527	527
2027
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.20%
Long-term debt	$ 750	750
2028
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Long-term debt	$ 2,000	2,000
2031
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.75%
Long-term debt	$ 466	466
2040
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	5.05%
Long-term debt	$ 300	300
2043
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Long-term debt	$ 950	950
2045
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.85%
Long-term debt	$ 600	600
2047
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	4.03%
Long-term debt	$ 2,250	2,250
Two Year Term [Member] [Domain]
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	1.89%
Credit facilities	$ 108	$ 134
Minimum \| 2026
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.75%
Maximum \| 2026
Long-Term Debt (Table Amounts) [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	7.88%

Long-Term Debt (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Maturities of Long-term Debt [Abstract]
2019	$ 517
2020	1,127
2021	741
2022	1,505
2023	1,053
Thereafter	9,532
Total principal payments	14,475
Unamortized premium on long-term debt, net of discount	(2)
Debt issuance costs	(73)	$ (82)
Total long-term debt	$ 14,400

Long-Term Debt (Details 3) £ in Millions	9 Months Ended	12 Months Ended
Long-Term Debt (Details 3) £ in Millions	Dec. 31, 2018 USD ($) Rate	Dec. 31, 2018 USD ($) Rate	Dec. 31, 2018 GBP (£) Rate	Sep. 30, 2018 USD ($)	May 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 08, 2015 USD ($)
Debt Instrument [Line Items]
Credit Facility, Covenant Terms, Maximum Debt to Capitalization Ratio		The company also cannot permit the ratio of its debt to capitalization (as set forth in the credit agreements) to exceed 65 percent.
Line of Credit Facility, Covenant Compliance		the company was in compliance with all covenants under its credit agreements.
Five Year Term [Member] [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,000,000,000	$ 2,000,000,000					$ 1,600,000,000
Credit facilities	0	0
Two Year Term [Member] [Domain]
Debt Instrument [Line Items]
Credit facilities	108,000,000	108,000,000				$ 134,000,000
Revolving Credit Facility [Member] \| Two Year Term [Member] [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 152,000,000	$ 152,000,000	£ 120
Credit facilities \| £			£ 85
London Interbank Offered Rate (LIBOR) [Member] \| Two Year Term [Member] [Domain]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate During Period \| Rate		1.10%
Commercial Paper [Member]
Debt Instrument [Line Items]
Short Term Debt, Maximum Borrowing Capacity				$ 2,000,000,000	$ 750,000,000
Debt Instrument, Term	3 months
Short-term Debt, Weighted Average Interest Rate, at Point in Time \| Rate	2.77%	2.77%	2.77%
Short-term Debt	$ 198,000,000	$ 198,000,000

Long-Term Debt (Details 4) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
Long-Term Debt (Details 4) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 06, 2018	Oct. 13, 2017
Debt Instrument [Line Items]
Long-term debt		$ 14,400
Long-term Debt, Fair Value		14,300	$ 16,000
Interest paid, net of interest received		$ 456	273	$ 299
Two Year Term [Member] [Domain]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.89%
October2017Notes [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 8,250
2020Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 1,000
Debt Instrument, Interest Rate, Stated Percentage						2.08%
2022Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 1,500
Debt Instrument, Interest Rate, Stated Percentage						2.55%
2025Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 1,500
Debt Instrument, Interest Rate, Stated Percentage						2.93%
2028Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 2,000
Debt Instrument, Interest Rate, Stated Percentage						3.25%
2047Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 2,250
Debt Instrument, Interest Rate, Stated Percentage						4.03%
April 2018 Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Repayments of Debt			$ 200
February 2027 Maturity [Domain] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 750			$ 750
Debt Instrument, Interest Rate, Stated Percentage	3.20%			3.20%
Debt Instrument, Maturity Date	Feb. 01, 2027
Orbital ATK [Member]
Debt Instrument [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt					$ 1,687

Investigations, Claims and Litigation Investigations, Claims and Litigation (Details) € in Millions, R$ in Millions, $ in Millions		3 Months Ended	12 Months Ended	63 Months Ended				65 Months Ended		67 Months Ended
	Dec. 28, 2018	Dec. 31, 2018 USD ($)	Dec. 31, 2007 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€)	Nov. 13, 2018 USD ($)	Nov. 13, 2018 BRL (R$)	Dec. 31, 2018 USD ($) Defendant	Dec. 31, 2018 BRL (R$) Defendant	Dec. 31, 2018 USD ($)	Feb. 16, 2018 USD ($)	May 04, 2012 USD ($)
US Government [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Paid, Value		$ 30
Solystic Matter [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value								$ 29	R$ 111
Counterclaim				$ 35	€ 31
Loss Contingency, Damages Awarded, Value						$ 11	R$ 41
Orbital ATK [Domain]
Loss Contingencies [Line Items]
Loss Contingency, Settlement Agreement, Terms	108
Unpaid Portions of Contract Price and Direct Costs Incurred [Member] \| United States Postal Service [Member]
Loss Contingencies [Line Items]
Receivables, unpaid long-term contracts												$ 63
Acts and Omissions with Adverse Affects on Performance and Obligations [Member] \| United States Postal Service [Member]
Loss Contingencies [Line Items]
Gain Contingency, Unrecorded Amount												$ 115
United States Postal Service [Member]
Loss Contingencies [Line Items]
Contract award			$ 875
United States Postal Service [Member] \| False Claims Act [Member] \| Threatened Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value										$ 179
Solystic Matter [Member] \| Solystic Matter [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Defendants \| Defendant								2	2
Initial Claim [Member] \| Solystic Matter [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value								$ 23	R$ 89
Incremental claim [Member] \| Solystic Matter [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value								6	R$ 22
Maximum \| United States Postal Service [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss		$ 410		$ 410				$ 410		$ 410
Updated claim [Member] \| United States Postal Service [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss											$ 193

Commitments and Contingencies (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Amounts accrued for probable environmental remediation costs	$ 461	$ 410
Recorded Third-Party Environmental Recoveries, Amount	343	207
Other Increase (Decrease) in Environmental Liabilities	103
Financial Arrangements (Amounts in Paragraph)
Unused standby letters of credit and bank guarantees	542
Surety Bond Outstanding	201
Other Current Liabilities [Member]
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Amounts accrued for probable environmental remediation costs	159
Other Noncurrent Liabilities [Member]
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Amounts accrued for probable environmental remediation costs	302
Inventoried Costs [Member]
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Recorded Third-Party Environmental Recoveries, Amount	127
Other Noncurrent Assets [Member]
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Recorded Third-Party Environmental Recoveries, Amount	216
Maximum \| Environmental Issue [Member]
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Loss Contingency, Estimate of Possible Loss	835	792
Minimum \| Environmental Issue [Member]
Environmental Commitments and Contingencies (Amounts in Paragraphs)
Loss Contingency, Estimate of Possible Loss	$ 447	$ 405

Commitments and Contingencies (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense for operating leases	$ 375	$ 300	$ 298
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	312
2020	270
2021	221
2022	186
2023	152
Thereafter	939
Total Minimum Lease Payments	$ 2,080

Retirement Benefits (Details 1) - USD ($) $ in Millions	12 Months Ended
Retirement Benefits (Details 1) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	$ (655)	$ 536	$ (950)
Pension Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	404	388	390
Interest cost	1,226	1,250	1,302
Expected return on plan assets	(2,217)	(1,885)	(1,853)
Amortization of prior service credit	(58)	(57)	(60)
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	(699)	445	(1,041)
Other	0	(7)	0
Net periodic benefit cost	54	(756)	820
Medical and Life Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	21	20	29
Interest cost	76	85	95
Expected return on plan assets	(101)	(89)	(86)
Amortization of prior service credit	(21)	(22)	(22)
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	44	91	91
Other	0	0	0
Net periodic benefit cost	$ (69)	$ (97)	$ (75)

Retirement Benefits (Details 2) - USD ($) $ in Millions	12 Months Ended
Retirement Benefits (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amortization of:
Prior service credit	$ 79	$ 79	$ 82
Tax expense (benefit) related to above items	(19)	(35)	(20)
Change in unamortized benefit plan costs	60	44	62
Pension Benefits
Amortization of:
Prior service credit	58	57	60
Tax expense (benefit) related to above items	(14)	(26)	(11)
Change in unamortized benefit plan costs	44	31	49
Medical and Life Benefits
Amortization of:
Prior service credit	21	22	22
Tax expense (benefit) related to above items	(5)	(9)	(9)
Change in unamortized benefit plan costs	$ 16	$ 13	$ 13

Retirement Benefits (Details 3) - USD ($) $ in Millions	12 Months Ended
Retirement Benefits (Details 3) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in plan assets
Fair value of plan assets at beginning of year	$ 28,564
Fair value of plan assets at end of year	28,397	$ 28,564
Amounts Recognized on the Balance Sheet
Non-current liability	(5,755)	(5,511)
Pension Benefits
Change in projected benefit obligation
Projected benefit obligation at beginning of year	31,967	30,409
Service cost	404	388	$ 390
Interest cost	1,226	1,250	1,302
Plan participants’ contributions	9	11
Actuarial (gain) loss	(2,561)	1,544
Benefits paid	(1,685)	(1,617)
Acquired benefit obligation	2,895	0
Other	(24)	(18)
Projected benefit obligation at end of year	32,231	31,967	30,409
Change in plan assets
Fair value of plan assets at beginning of year	27,226	24,384
Net gain on plan assets	(1,043)	3,885
Employer contributions	370	596
Plan participants’ contributions	9	11
Benefits paid	(1,685)	(1,617)
Acquired plan assets	2,293	0
Other	(20)	(33)
Fair value of plan assets at end of year	27,150	27,226	24,384
Funded status	(5,081)	(4,741)
Amounts Recognized on the Balance Sheet
Non-current assets	77	82
Current liability	(164)	(154)
Non-current liability	(4,994)	(4,669)
Medical and Life Benefits
Change in projected benefit obligation
Projected benefit obligation at beginning of year	2,110	2,100
Service cost	21	20	29
Interest cost	76	85	95
Plan participants’ contributions	25	24
Actuarial (gain) loss	(211)	26
Benefits paid	(148)	(144)
Acquired benefit obligation	50	0
Other	7	(1)
Projected benefit obligation at end of year	1,930	2,110	2,100
Change in plan assets
Fair value of plan assets at beginning of year	1,338	1,208
Net gain on plan assets	(65)	208
Employer contributions	38	45
Plan participants’ contributions	25	24
Benefits paid	(148)	(144)
Acquired plan assets	58	0
Other	1	(3)
Fair value of plan assets at end of year	1,247	1,338	$ 1,208
Funded status	(683)	(772)
Amounts Recognized on the Balance Sheet
Non-current assets	124	112
Current liability	(46)	(42)
Non-current liability	$ (761)	$ (842)

Retirement Benefits (Details 4) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pension plans with accumulated benefit obligations in excess of fair value of plan assets (Table Amounts) [Abstract]
Projected benefit obligation	$ 30,259	$ 29,804
Accumulated benefit obligation	29,961	29,454
Fair value of plan assets	$ 25,101	$ 24,981

Retirement Benefits (Details 5)	12 Months Ended
Retirement Benefits (Details 5)	Dec. 31, 2018	Dec. 31, 2017
Benefit Obligation [Member]
Defined Benefit Plan Disclosure (Table Amounts)
Initial health care cost trend rate assumed for the next year	6.20%	6.50%
Rate to which the health care cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%
Year that the health care cost trend rate reaches the ultimate trend rate	2023	2023
Pension Benefits
Assumptions Used to Determine Benefit Obligation
Discount rate	4.31%	3.68%
Initial cash balance crediting rate assumed for the next year	3.00%	2.75%
Rate to which the cash balance crediting rate is assumed to increase (the ultimate rate)	3.25%	3.00%
Year that the cash balance crediting rate reaches the ultimate rate	2024	2023
Rate of compensation increase	3.00%	3.00%
Assumptions Used to Determine Benefit Cost
Discount rate	3.68%	4.19%
Initial cash balance crediting rate assumed for the next year	2.75%	3.10%
Rate to which the cash balance crediting rate is assumed to increase (the ultimate rate)	3.00%	3.60%
Year that the cash balance crediting rate reaches the ultimate rate	2023	2022
Expected long-term return on plan assets	8.00%	8.00%
Rate of compensation increase	3.00%	3.00%
Post-retirement Benefit Cost [Member]
Defined Benefit Plan Disclosure (Table Amounts)
Initial health care cost trend rate assumed for the next year	6.50%	6.50%
Rate to which the health care cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%
Year that the health care cost trend rate reaches the ultimate trend rate	2023	2020
Medical and Life Benefits
Assumptions Used to Determine Benefit Obligation
Discount rate	4.30%	3.66%
Assumptions Used to Determine Benefit Cost
Discount rate	3.66%	4.13%
Expected long-term return on plan assets	7.65%	7.70%

Retirement Benefits (Details 6)	Dec. 31, 2018
Cash and Cash Equivalents [Member] \| Minimum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Cash and Cash Equivalents [Member] \| Maximum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	12.00%
Equity Securities [Member] \| Minimum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	35.00%
Equity Securities [Member] \| Maximum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	55.00%
Fixed income securities \| Minimum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	20.00%
Fixed income securities \| Maximum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	40.00%
Alternative investments \| Minimum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	13.00%
Alternative investments \| Maximum
Plan Asset Allocation Ranges (Table Amounts) [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	33.00%

Retirement Benefits (Details 7) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	$ 28,397	$ 28,564
Cash & cash equivalents
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,864	4,141
U.S. Equity Securities [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,859	3,366
Alternative Investment, Net Asset Value	1,170	1,053
International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,712	2,454
Alternative Investment, Net Asset Value	4,017	4,315
U.S. Treasuries
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,527	1,282
U.S. Government Agency
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	322	345
Non-U.S. Government
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	206	135
Corporate debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	4,175	4,406
Asset backed
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	297	255
High yield debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	164	866
Bank loans
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	20	248
Other
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	68	20
Fixed Income Funds
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Alternative Investment, Net Asset Value	1,386	129
Hedge Funds
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Alternative Investment, Net Asset Value	351	166
OpportunisticFunds
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Alternative Investment, Net Asset Value	1,367	873
Private Equity Funds [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Alternative Investment, Net Asset Value	2,510	2,091
Real Estate Funds [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Alternative Investment, Net Asset Value	2,382	2,419
Level 1
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	5,865	5,888
Level 1 \| Cash & cash equivalents
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	209	55
Level 1 \| U.S. Equity Securities [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,859	3,365
Level 1 \| International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,711	2,453
Level 1 \| U.S. Treasuries
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	26	0
Level 1 \| Corporate debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	34	0
Level 1 \| High yield debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	11	0
Level 1 \| Other
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	15	15
Level 2
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	9,346	11,626
Level 2 \| Cash & cash equivalents
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2,655	4,086
Level 2 \| U.S. Treasuries
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1,501	1,282
Level 2 \| U.S. Government Agency
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	322	345
Level 2 \| Non-U.S. Government
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	206	135
Level 2 \| Corporate debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	4,141	4,406
Level 2 \| Asset backed
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	297	255
Level 2 \| High yield debt
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	153	866
Level 2 \| Bank loans
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	20	248
Level 2 \| Other
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	51	3
Level 3
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	3	4
Level 3 \| U.S. Equity Securities [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets		1
Level 3 \| International equities
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	1	1
Level 3 \| Other
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Fair value of plan assets	2	2
Pension and Other Post-retirement benefit plans [Member]
Plan Assets by Fair Value Measurement Input (Table Amounts) [Abstract]
Derivative Asset	76	34
Derivative Liability	(52)	(19)
Derivatives, notional amount	$ 3,200	$ 3,300

Retirement Benefits (Details 8) $ in Millions	Dec. 31, 2018 USD ($)
Estimated Benefit Payments (Table Amounts) [Abstract]
2019	$ 1,934
2020	1,989
2021	2,022
2022	2,069
2023	2,109
2024 through 2028	11,035
Pension Benefits
Estimated Benefit Payments (Table Amounts) [Abstract]
2019	1,781
2020	1,834
2021	1,880
2022	1,928
2023	1,970
2024 through 2028	10,384
Medical and Life Benefits
Estimated Benefit Payments (Table Amounts) [Abstract]
2019	153
2020	155
2021	142
2022	141
2023	139
2024 through 2028	$ 651

Retirement Benefits (Details 9) - USD ($) $ in Millions	12 Months Ended
Retirement Benefits (Details 9) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 403	$ 344	$ 311
Pension and post-retirement benefits disclosures (Amounts in paragraphs)
Accumulated benefit obligation for all defined benefit pension plans	31,900	31,600
Pension Benefits
Defined Benefit Plan Disclosure (Table Amounts)
Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year	59
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Expected 2019 employer contributions	91
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Defined Benefit Plan, Plan Assets, Contributions by Employer	370	596
Pension Benefits \| Voluntary Contributions [Member]
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Defined Benefit Plan, Plan Assets, Contributions by Employer	280
OPB contributions
Defined Benefit Plan Disclosure (Table Amounts)
Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year	3
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Expected 2019 employer contributions	50
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 38	45
Defined Benefit Plan, Interest on Service Cost is reclassified to Interest Cost [Member] \| Pension Benefits
Defined Benefit Plan Disclosure (Table Amounts)
Prior Period Reclassification Adjustment		16	18
Defined Benefit Plan, Administrative Expenses of the Service Cost reclassified to Net Actuarial Loss [Member] \| Pension Benefits
Defined Benefit Plan Disclosure (Table Amounts)
Prior Period Reclassification Adjustment		20	38
Defined Benefit Plan, Administrative Expenses of the Service Cost reclassified to Net Actuarial Loss [Member] \| OPB contributions
Defined Benefit Plan Disclosure (Table Amounts)
Prior Period Reclassification Adjustment		2	$ 1
U.S. Equity Securities [Member]
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	Monthly
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
International Equity Securities [Member]
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	Monthly
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
Fixed Income Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 0	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	daily, monthly or quarterly
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
Hedge Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 0	0
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Frequency	monthly or quarterly
OpportunisticFunds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 1,100	768
Private Equity Funds [Member]
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 1,800	1,400
Average investment term, alternative investments	10 years
Real Estate Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 73	$ 71
Average investment term, alternative investments	10 years
Minimum \| Hedge Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
Minimum \| OpportunisticFunds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Average investment term, alternative investments	5 years
Maximum \| Hedge Funds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	95 days
Maximum \| OpportunisticFunds
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Average investment term, alternative investments	10 years

Stock Compensation Plans and Other Compensation Arrangements (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	$ 86	$ 94	$ 93
Tax benefits from stock-based compensation expense	$ 27	$ 48	$ 85

Stock Compensation Plans and Other Compensation Arrangements (Details 2) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation by Share-based Payment Award
Stock awards, outstanding, weighted average remaining contractual terms	9 months 18 days	1 year	1 year 3 months	1 year 2 months
Stock Award Activity (Table)
Stock awards - outstanding at period start	938	1,148	1,586
Stock awards - granted	376	397	483
Stock awards - vested	(455)	(521)	(872)
Stock awards - forfeited	(63)	(86)	(49)
Stock awards - outstanding at period end	796	938	1,148	1,586
Stock Awards, Weighted Average Grant Date Fair Value [Table]
Weighted-average grant date fair value - outstanding at period start	$ 192	$ 167	$ 122
Weighted-average grant date fair value - granted	321	233	186
Weighted-average grant date fair value - vested	181	152	97
Weighted-average grant date fair value - forfeited	250	198	143
Weighted-average grant date fair value - outstanding at period end	$ 244	$ 192	$ 167	$ 122

Stock Compensation Plans and Other Compensation Arrangements (Details 3) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation by Share-based Payment Award
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 108
Weighted-average period for unrecognized compensation expense to be charged to expense	1 year 3 months
Stock plans, vesting period	3 years
Stock issued, settlement of fully vested stock awards, fair value grant date	$ 93	$ 96	$ 97
Available for future grant	5.1
2011 Long-Term Incentive Stock Plan
Share-based Compensation by Share-based Payment Award
Available for future grant	5.9
Amended 2011 Plan [Domain]
Share-based Compensation by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	2.4
Minimum
Share-based Compensation by Share-based Payment Award
Required service period under 2011 Plan and 1993 SPND (years)	5 years
Minimum \| Grants During 2010 and After [Member]
Share-based Compensation by Share-based Payment Award
Share Based Compensation Arrangement By Share Based Payment Award Award Grants Percentage Financial Metric Met Exceeded	0.00%
Maximum \| Grants During 2010 and After [Member]
Share-based Compensation by Share-based Payment Award
Share Based Compensation Arrangement By Share Based Payment Award Award Grants Percentage Financial Metric Met Exceeded	200.00%
Cash Units and Cash Performance Units [Member]
Share-based Compensation by Share-based Payment Award
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 137
Cash Units and Cash Performance Units [Member] \| Minimum
Share-based Compensation by Share-based Payment Award
Deferred Compensation Cash-based Arrangements, Liability, Current	36	38	39
Cash Units and Cash Performance Units [Member] \| Maximum
Share-based Compensation by Share-based Payment Award
Deferred Compensation Cash-based Arrangements, Liability, Current	$ 205	$ 201	$ 199

Segment Information (Details 1) $ in Millions	3 Months Ended								12 Months Ended
Segment Information (Details 1) $ in Millions	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Number of reportable segments									4
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Operating income	$ 943	$ 1,172	$ 817	$ 848	$ 672	$ 829	$ 864	$ 853	3,780	3,218	3,277
Operating Segments
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									3,447	2,903	2,864
Operating Segments \| Aerospace Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									13,096	12,131	10,853
Operating income									1,411	1,289	1,198
Operating Segments \| Innovation Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									3,276	0	0
Operating income									343	0	0
Operating Segments \| Mission Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									11,709	11,470	11,161
Operating income									1,520	1,442	1,468
Operating Segments \| Technology Services
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									4,297	4,687	4,765
Operating income									443	449	456
Intersegment sales
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									2,283	2,284	2,073
Operating income									270	277	258
Intersegment sales \| Aerospace Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									197	295	240
Operating income									23	33	28
Intersegment sales \| Innovation Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									127	0	0
Operating income									1	0	0
Intersegment sales \| Mission Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									1,145	954	875
Operating income									165	141	136
Intersegment sales \| Technology Services
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									814	1,035	958
Operating income									81	103	94
Net FAS (service)/CAS pension adjustment
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									613	638	457
Corporate, Non-Segment [Member]
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									(277)	(319)	(39)
Segment Reconciling Items [Member]
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income									$ (3)	$ (4)	$ (5)

Segment Information (Details 2) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
Segment Information (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Major Customer [Line Items]
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Concentration Risk, Percentage									100.00%	100.00%	100.00%
US Government
Revenue, Major Customer [Line Items]
Sales									$ 24,796	$ 21,969	$ 20,736
Concentration Risk, Percentage									82.00%	85.00%	84.00%
US Government \| Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 11,380	$ 10,521	$ 9,277
Concentration Risk, Percentage									87.00%	87.00%	86.00%
US Government \| Innovation Systems
Revenue, Major Customer [Line Items]
Sales									$ 2,241	$ 0	$ 0
Concentration Risk, Percentage									68.00%	0.00%	0.00%
US Government \| Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 8,803	$ 8,876	$ 8,737
Concentration Risk, Percentage									75.00%	77.00%	78.00%
US Government \| Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales									$ 2,372	$ 2,572	$ 2,722
Concentration Risk, Percentage									55.00%	55.00%	57.00%
International
Revenue, Major Customer [Line Items]
Sales									$ 4,434	$ 3,452	$ 3,295
Concentration Risk, Percentage									15.00%	13.00%	13.00%
International \| Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 1,371	$ 1,160	$ 1,192
Concentration Risk, Percentage									10.00%	10.00%	11.00%
International \| Innovation Systems
Revenue, Major Customer [Line Items]
Sales									$ 615	$ 0	$ 0
Concentration Risk, Percentage									19.00%	0.00%	0.00%
International \| Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 1,647	$ 1,540	$ 1,416
Concentration Risk, Percentage									14.00%	14.00%	13.00%
International \| Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales									$ 801	$ 752	$ 687
Concentration Risk, Percentage									19.00%	16.00%	15.00%
Other Customers
Revenue, Major Customer [Line Items]
Sales									$ 865	$ 583	$ 675
Concentration Risk, Percentage									3.00%	2.00%	3.00%
Other Customers \| Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 148	$ 155	$ 144
Concentration Risk, Percentage									1.00%	1.00%	1.00%
Other Customers \| Innovation Systems
Revenue, Major Customer [Line Items]
Sales									$ 293	$ 0	$ 0
Concentration Risk, Percentage									9.00%	0.00%	0.00%
Other Customers \| Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 114	$ 100	$ 133
Concentration Risk, Percentage									1.00%	1.00%	1.00%
Other Customers \| Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales									$ 310	$ 328	$ 398
Concentration Risk, Percentage									7.00%	7.00%	8.00%
Intersegment sales \| Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 197	$ 295	$ 240
Concentration Risk, Percentage									2.00%	2.00%	2.00%
Intersegment sales \| Innovation Systems
Revenue, Major Customer [Line Items]
Sales									$ 127	$ 0	$ 0
Concentration Risk, Percentage									4.00%	0.00%	0.00%
Intersegment sales \| Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 1,145	$ 954	$ 875
Concentration Risk, Percentage									10.00%	8.00%	8.00%
Intersegment sales \| Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales									$ 814	$ 1,035	$ 958
Concentration Risk, Percentage									19.00%	22.00%	20.00%
Operating Segments [Member] \| Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 13,096	$ 12,131	$ 10,853
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Operating Segments [Member] \| Innovation Systems
Revenue, Major Customer [Line Items]
Sales									$ 3,276	$ 0	$ 0
Concentration Risk, Percentage									100.00%	0.00%	0.00%
Operating Segments [Member] \| Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales									$ 11,709	$ 11,470	$ 11,161
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Operating Segments [Member] \| Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales									$ 4,297	$ 4,687	$ 4,765
Concentration Risk, Percentage									100.00%	100.00%	100.00%

Segment Information (Details 3) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
Segment Information (Details 3) - USD ($) $ in Millions	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Contract Type [Line Items]
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Operating Segments [Member] \| Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 13,096	$ 12,131	$ 10,853
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Operating Segments [Member] \| Innovation Systems
Revenue, Contract Type [Line Items]
Sales									$ 3,276	$ 0	$ 0
Concentration Risk, Percentage									100.00%	0.00%	0.00%
Operating Segments [Member] \| Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 11,709	$ 11,470	$ 11,161
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Operating Segments [Member] \| Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales									$ 4,297	$ 4,687	$ 4,765
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Cost-type
Revenue, Contract Type [Line Items]
Sales									$ 15,004	$ 14,197	$ 13,454
Concentration Risk, Percentage									50.00%	55.00%	54.00%
Cost-type \| Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 7,634	$ 7,193	$ 6,484
Concentration Risk, Percentage									59.00%	61.00%	61.00%
Cost-type \| Innovation Systems
Revenue, Contract Type [Line Items]
Sales									$ 843	$ 0	$ 0
Concentration Risk, Percentage									27.00%	0.00%	0.00%
Cost-type \| Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 4,939	$ 5,311	$ 5,200
Concentration Risk, Percentage									47.00%	51.00%	51.00%
Cost-type \| Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales									$ 1,588	$ 1,693	$ 1,770
Concentration Risk, Percentage									46.00%	46.00%	46.00%
Fixed-price
Revenue, Contract Type [Line Items]
Sales									$ 15,091	$ 11,807	$ 11,252
Concentration Risk, Percentage									50.00%	45.00%	46.00%
Fixed-price \| Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 5,265	$ 4,643	$ 4,129
Concentration Risk, Percentage									41.00%	39.00%	39.00%
Fixed-price \| Innovation Systems
Revenue, Contract Type [Line Items]
Sales									$ 2,306	$ 0	$ 0
Concentration Risk, Percentage									73.00%	0.00%	0.00%
Fixed-price \| Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 5,625	$ 5,205	$ 5,086
Concentration Risk, Percentage									53.00%	49.00%	49.00%
Fixed-price \| Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales									$ 1,895	$ 1,959	$ 2,037
Concentration Risk, Percentage									54.00%	54.00%	54.00%
Intersegment sales \| Aerospace Systems [Member]
Revenue, Contract Type [Line Items]
Sales									$ 197	$ 295	$ 240
Intersegment sales \| Innovation Systems
Revenue, Contract Type [Line Items]
Sales									127	0	0
Intersegment sales \| Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales									1,145	954	875
Intersegment sales \| Technology Services [Member]
Revenue, Contract Type [Line Items]
Sales									$ 814	$ 1,035	$ 958

Segment Information (Details 4) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
Segment Information (Details 4) - USD ($) $ in Millions	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Concentration Risk, Percentage									100.00%	100.00%	100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 25,661	$ 22,552	$ 21,411
Concentration Risk, Percentage									85.00%	87.00%	87.00%
Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 1,666	$ 1,461	$ 1,212
Concentration Risk, Percentage									6.00%	5.00%	5.00%
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 2,768	$ 1,991	$ 2,083
Concentration Risk, Percentage									9.00%	8.00%	8.00%
Aerospace Systems [Member] \| United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 11,528	$ 10,676	$ 9,421
Concentration Risk, Percentage									89.00%	90.00%	89.00%
Aerospace Systems [Member] \| Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 705	$ 649	$ 579
Concentration Risk, Percentage									6.00%	6.00%	5.00%
Aerospace Systems [Member] \| All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 666	$ 511	$ 613
Concentration Risk, Percentage									5.00%	4.00%	6.00%
Aerospace Systems [Member] \| Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 197	$ 295	$ 240
Aerospace Systems [Member] \| Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 13,096	$ 12,131	$ 10,853
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Innovation Systems \| United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 2,534	$ 0	$ 0
Concentration Risk, Percentage									80.00%	0.00%	0.00%
Innovation Systems \| Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 151	$ 0	$ 0
Concentration Risk, Percentage									5.00%	0.00%	0.00%
Innovation Systems \| All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 464	$ 0	$ 0
Concentration Risk, Percentage									15.00%	0.00%	0.00%
Innovation Systems \| Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 127	$ 0	$ 0
Innovation Systems \| Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 3,276	$ 0	$ 0
Concentration Risk, Percentage									100.00%	0.00%	0.00%
Mission Systems [Member] \| United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 8,917	$ 8,976	$ 8,870
Concentration Risk, Percentage									85.00%	86.00%	86.00%
Mission Systems [Member] \| Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 659	$ 671	$ 514
Concentration Risk, Percentage									6.00%	6.00%	5.00%
Mission Systems [Member] \| All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 988	$ 869	$ 902
Concentration Risk, Percentage									9.00%	8.00%	9.00%
Mission Systems [Member] \| Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 1,145	$ 954	$ 875
Mission Systems [Member] \| Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 11,709	$ 11,470	$ 11,161
Concentration Risk, Percentage									100.00%	100.00%	100.00%
Technology Services [Member] \| United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 2,682	$ 2,900	$ 3,120
Concentration Risk, Percentage									77.00%	79.00%	82.00%
Technology Services [Member] \| Asia/Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 151	$ 141	$ 119
Concentration Risk, Percentage									4.00%	4.00%	3.00%
Technology Services [Member] \| All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 650	$ 611	$ 568
Concentration Risk, Percentage									19.00%	17.00%	15.00%
Technology Services [Member] \| Intersegment sales
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 814	$ 1,035	$ 958
Technology Services [Member] \| Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									$ 4,297	$ 4,687	$ 4,765
Concentration Risk, Percentage									100.00%	100.00%	100.00%

Segment Information (Details 5) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
Segment Information (Details 5) - USD ($) $ in Millions	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income	$ 943	$ 1,172	$ 817	$ 848	$ 672	$ 829	$ 864	$ 853	3,780	3,218	3,277
Intersegment sales
Segment Reporting Information [Line Items]
Sales									2,283	2,284	2,073
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									270	277	258
Intersegment sales \| Aerospace Systems
Segment Reporting Information [Line Items]
Sales									197	295	240
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									23	33	28
Intersegment sales \| Innovation Systems
Segment Reporting Information [Line Items]
Sales									127	0	0
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									1	0	0
Intersegment sales \| Mission Systems
Segment Reporting Information [Line Items]
Sales									1,145	954	875
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									165	141	136
Intersegment sales \| Technology Services
Segment Reporting Information [Line Items]
Sales									814	1,035	958
Intersegment sales and operating income (Table Amounts) [Abstract]
Operating income									$ 81	$ 103	$ 94

Segment Information (Details 6) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 37,653	$ 35,128
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	34,122	21,900
Operating Segments [Member] \| Aerospace Systems
Segment Reporting Information [Line Items]
Total assets	9,750	8,497
Operating Segments [Member] \| Innovation Systems
Segment Reporting Information [Line Items]
Total assets	10,368	0
Operating Segments [Member] \| Mission Systems
Segment Reporting Information [Line Items]
Total assets	11,047	10,389
Operating Segments [Member] \| Technology Services
Segment Reporting Information [Line Items]
Total assets	2,957	3,014
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 3,531	$ 13,228

Segment Information (Details 7) - USD ($) $ in Millions	12 Months Ended
Segment Information (Details 7) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	$ 1,249	$ 928	$ 920
Depreciation and amortization	800	475	456
Aerospace Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	781	665	451
Depreciation and amortization	243	234	216
Innovation Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	141	0	0
Depreciation and amortization	84	0	0
Mission Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	206	164	372
Depreciation and amortization	134	131	140
Technology Services
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	18	15	6
Depreciation and amortization	45	40	37
Corporate
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	103	84	91
Depreciation and amortization	$ 294	$ 70	$ 63

Unaudited Selected Quarterly Data (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unaudited Selected Quarterly Data (Table Amounts) [Abstract]
Sales	$ 8,156	$ 8,085	$ 7,119	$ 6,735	$ 6,552	$ 6,569	$ 6,473	$ 6,410	$ 30,095	$ 26,004	$ 24,706
Operating income	943	1,172	817	848	672	829	864	853	3,780	3,218	3,277
Net earnings	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Basic earnings per share	$ 2.07	$ 7.15	$ 4.52	$ 4.82	$ 3.86	$ 4.31	$ 3.88	$ 4.41	$ 18.59	$ 16.45	$ 11.42
Diluted earnings per share	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Weighted-average common shares outstanding	171.8	174.1	174.5	174.3	174.2	174.2	174.5	174.8	173.7	174.4	178.9
Weighted-average diluted shares outstanding	172.6	174.9	175.4	175.4	175.5	175.3	175.5	176.1	174.6	175.6	180.5

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

2018 Impact of Accounting Method Change (Details 1) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
General and Administrative Expense									$ 3,011	$ 2,712	$ 2,632
Operating Income (Loss)	$ 943	$ 1,172	$ 817	$ 848	$ 672	$ 829	$ 864	$ 853	3,780	3,218	3,277
Interest and Debt Expense									(562)	(360)	(301)
Net FAS (non-service) pension benefit									1,049	699	611
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Other Nonoperating Income (Expense)									130	136	44
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									3,742	4,229	2,681
Income Tax Expense (Benefit)									513	1,360	638
Net Income (Loss) Attributable to Parent	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Earnings Per Share, Basic	$ 2.07	$ 7.15	$ 4.52	$ 4.82	$ 3.86	$ 4.31	$ 3.88	$ 4.41	$ 18.59	$ 16.45	$ 11.42
Earnings Per Share, Diluted	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
General and Administrative Expense										$ 0	$ 0
Operating Income (Loss)	$ 23	$ (6)	$ (6)	$ (6)	$ (32)	$ (8)	$ (9)	$ (9)	$ 5	(58)	8
Interest and Debt Expense									0	0	0
Net FAS (non-service) pension benefit									535	743	752
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Other Nonoperating Income (Expense)									(2)	12	16
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									(117)	1,233	(174)
Income Tax Expense (Benefit)									(24)	359	(61)
Net Income (Loss) Attributable to Parent	$ (394)	$ 100	$ 100	$ 101	$ 525	$ 107	$ 122	$ 120	$ (93)	$ 874	$ (113)
Earnings Per Share, Basic	$ (2.29)	$ 0.58	$ 0.57	$ 0.58	$ 3.01	$ 0.62	$ 0.70	$ 0.69	$ (0.53)	$ 5.01	$ (0.63)
Earnings Per Share, Diluted	$ (2.28)	$ 0.57	$ 0.57	$ 0.58	$ 2.99	$ 0.61	$ 0.70	$ 0.68	$ (0.54)	$ 4.98	$ (0.63)
Method Prior to change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Income (Loss)									$ 3,775
Interest and Debt Expense									(562)
Net FAS (non-service) pension benefit									514
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									0
Other Nonoperating Income (Expense)									132
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									3,859
Income Tax Expense (Benefit)									537
Net Income (Loss) Attributable to Parent									$ 3,322
Earnings Per Share, Basic									$ 19.12
Earnings Per Share, Diluted									$ 19.03
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										$ 2,869	$ 2,043
Retained Earnings [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										$ 874	$ (113)

2018 Impact of Accounting Method Change (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained Earnings (Accumulated Deficit)	$ 8,068	$ 6,913
Accumulated Other Comprehensive Income (Loss), Net of Tax	(52)	1
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained Earnings (Accumulated Deficit)	(5,897)	(4,719)
Accumulated Other Comprehensive Income (Loss), Net of Tax	5,897	$ 4,719
Method Prior to change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained Earnings (Accumulated Deficit)	13,965
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (5,949)

2018 Impact of Accounting Method Change (Details 3) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Depreciation, Depletion and Amortization									800	475	456
Mark-to-market pension and OPEB Benefit									655	(536)	950
Deferred income taxes									234	985	(60)
Stock-based compensation									86	94	93
Accounts receivable, net									202	(209)	46
Unbilled receivables, net									(297)	(422)	(211)
Inventoried costs, net									(37)	25	(53)
Prepaid expenses and other assets									(56)	(92)	(117)
Accounts payable and other liabilities									381	570	18
Retiree benefits									(1,083)	(946)	(375)
Other, net									(29)	(43)	(125)
Income taxes payable, net									(258)	(157)	148
Net cash provided by operating activities									3,827	2,613	2,813
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent	$ (394)	$ 100	$ 100	$ 101	$ 525	$ 107	$ 122	$ 120	(93)	874	(113)
Depreciation, Depletion and Amortization									0	0	0
Mark-to-market pension and OPEB Benefit									(655)
Deferred income taxes									(29)	417	(69)
Stock-based compensation									0	0	0
Accounts receivable, net									0	0	0
Unbilled receivables, net									0	0	0
Inventoried costs, net									0	0	0
Prepaid expenses and other assets									0	0	0
Accounts payable and other liabilities									0	0	0
Retiree benefits									(533)	(755)	(768)
Other, net									0	0	0
Income taxes payable, net									0	0	0
Net cash provided by operating activities									0	0	0
Method Prior to change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent									3,322
Depreciation, Depletion and Amortization									800
Mark-to-market pension and OPEB Benefit									0
Deferred income taxes									263
Stock-based compensation									86
Accounts receivable, net									202
Unbilled receivables, net									297
Inventoried costs, net									(37)
Prepaid expenses and other assets									(56)
Accounts payable and other liabilities									381
Retiree benefits									(550)
Other, net									(29)
Income taxes payable, net									(258)
Net cash provided by operating activities									$ 3,827
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										2,869	2,043
Retained Earnings [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										$ 874	$ (113)

2018 Impact of Accounting Method Change (Details 4) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	$ 8,187				$ 7,132				$ 8,187	$ 7,132	$ 5,363
Other comprehensive loss, net of tax									(74)	(46)	(113)
Net Income (Loss) Attributable to Parent	356	$ 1,244	$ 789	$ 840	672	$ 750	$ 677	$ 770	3,229	2,869	2,043
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					0					0	0
Other comprehensive loss, net of tax									93	(874)	113
Stock Repurchased and Retired During Period, Value									0
Net Income (Loss) Attributable to Parent	(394)	$ 100	$ 100	$ 101	525	$ 107	$ 122	$ 120	(93)	874	(113)
Dividends, Common Stock									0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures									0
Method Prior to change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other comprehensive loss, net of tax									(167)
Stock Repurchased and Retired During Period, Value									1,225
Net Income (Loss) Attributable to Parent									3,322
Dividends, Common Stock									822
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures									(6)
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	8,068				6,913				8,068	6,913	5,141	$ 5,329
Impact from adoption of ASU 2018-02 and ASU 2016-01									(21)	0	0
Stock Repurchased and Retired During Period, Value									1,225	371	1,548
Net Income (Loss) Attributable to Parent										2,869	2,043
Dividends, Common Stock									822	687	633
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures									(6)	(39)	(50)
Retained Earnings [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	(5,897)				(4,719)				(5,897)	(4,719)	(5,593)	(5,480)
Impact from adoption of ASU 2018-02 and ASU 2016-01									(1,085)
Stock Repurchased and Retired During Period, Value										0	0
Net Income (Loss) Attributable to Parent										874	(113)
Dividends, Common Stock										0	0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures										0	0
Retained Earnings [Member] \| Method Prior to change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	13,965				11,632				13,965	11,632
Impact from adoption of ASU 2018-02 and ASU 2016-01									1,064
AOCI Attributable to Parent [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	(52)				1				(52)	1	47	160
Impact from adoption of ASU 2018-02 and ASU 2016-01									21	0	0
Other comprehensive loss, net of tax									(74)	(46)	(113)
AOCI Attributable to Parent [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	5,897				4,719				5,897	4,719	5,593	$ 5,480
Impact from adoption of ASU 2018-02 and ASU 2016-01									1,085
Other comprehensive loss, net of tax										(874)	$ 113
AOCI Attributable to Parent [Member] \| Method Prior to change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	$ (5,949)				$ (4,718)				(5,949)	$ (4,718)
Impact from adoption of ASU 2018-02 and ASU 2016-01									$ (1,064)

Recast 2017 and 2016 Financial Information (Details 1) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 1,579				$ 11,225				$ 1,579	$ 11,225	$ 2,541	$ 2,319
Revenues	8,156	$ 8,085	$ 7,119	$ 6,735	6,552	$ 6,569	$ 6,473	$ 6,410	30,095	26,004	24,706
General and Administrative Expense									3,011	2,712	2,632
Operating Income (Loss)	943	1,172	817	848	672	829	864	853	3,780	3,218	3,277
Interest and Debt Expense									562	360	301
Net FAS (non-service) pension benefit									1,049	699	611
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Other Nonoperating Income (Expense)									130	136	44
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									3,742	4,229	2,681
Income Tax Expense (Benefit)									513	1,360	638
Net Income (Loss) Attributable to Parent	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Earnings Per Share, Basic	$ 2.07	$ 7.15	$ 4.52	$ 4.82	$ 3.86	$ 4.31	$ 3.88	$ 4.41	$ 18.59	$ 16.45	$ 11.42
Weighted Average Number of Shares Outstanding, Basic	171,800,000	174,100,000	174,500,000	174,300,000	174,200,000	174,200,000	174,500,000	174,800,000	173,700,000	174,400,000	178,900,000
Earnings Per Share, Diluted	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Weighted Average Number of Shares Outstanding, Diluted	172,600,000	174,900,000	175,400,000	175,400,000	175,500,000	175,300,000	175,500,000	176,100,000	174,600,000	175,600,000	180,500,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax									$ 60	$ 44	$ 62
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax									(8)	(4)	(50)
Other, net									(6)	2	(1)
Other comprehensive loss, net of tax									(74)	(46)	(113)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									3,155	2,823	1,930
Accounts receivable, net	$ 1,448				$ 1,054				1,448	1,054
Unbilled receivables, net	5,026				3,465				5,026	3,465
Inventoried costs, net	654				398				654	398
Other Assets, Current	973				445				973	445
Assets, Current	9,680				16,587				9,680	16,587
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017	6,372				4,225				6,372	4,225
Goodwill	18,672				12,455				18,672	12,455	12,450
Intangible assets, net	1,372				52				1,372	52
Deferred tax assets	94				447				94	447
Other non-current assets	1,463				1,362				1,463	1,362
Assets	37,653				35,128				37,653	35,128
Accounts Payable, Current	2,182				1,661				2,182	1,661
Employee-related Liabilities, Current	1,676				1,382				1,676	1,382
Customer Advances, Current	1,917				1,761				1,917	1,761
Other Liabilities, Current	2,499				2,288				2,499	2,288
Liabilities, Current	8,274				7,092				8,274	7,092
Long-term Debt and Capital Lease Obligations	13,883				14,399				13,883	14,399
Liability, Defined Benefit Plan, Noncurrent	5,755				5,511				5,755	5,511
Other Liabilities, Noncurrent	1,446				994				1,446	994
Liabilities	29,466				27,996				29,466	27,996
Preferred Stock, Value, Issued	0				0				0	0
Common Stock, Value, Issued	171				174				171	174
Paid-in capital	0				44				0	44
Retained Earnings (Accumulated Deficit)	8,068				6,913				8,068	6,913
Accumulated Other Comprehensive Income (Loss), Net of Tax	(52)				1				(52)	1
Stockholders' Equity Attributable to Parent	8,187				7,132				8,187	7,132	5,363
Liabilities and Equity	37,653				35,128				37,653	35,128
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value					11,225					11,225
Revenues										25,803	24,508
General and Administrative Expense										2,655	2,584
Operating Income (Loss)										3,299	3,193
Interest and Debt Expense										360	301
Net FAS (non-service) pension benefit										0	0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Other Nonoperating Income (Expense)										110	31
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										3,049	2,923
Income Tax Expense (Benefit)										1,034	723
Net Income (Loss) Attributable to Parent										$ 2,015	$ 2,200
Earnings Per Share, Basic										$ 11.55	$ 12.30
Weighted Average Number of Shares Outstanding, Basic										174,400,000	178,900,000
Earnings Per Share, Diluted										$ 11.47	$ 12.19
Weighted Average Number of Shares Outstanding, Diluted										175,600,000	180,500,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ 830	$ 175
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										(4)	(50)
Other, net										2	(1)
Other comprehensive loss, net of tax										828	(226)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										2,843	1,974
Accounts receivable, net					829					829
Unbilled receivables, net					3,147					3,147
Inventoried costs, net					780					780
Other Assets, Current					368					368
Assets, Current					16,349					16,349
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017					4,225					4,225
Goodwill					12,455					12,455
Intangible assets, net					52					52
Deferred tax assets					475					475
Other non-current assets					1,361					1,361
Assets					34,917					34,917
Accounts Payable, Current					1,661					1,661
Employee-related Liabilities, Current					1,382					1,382
Customer Advances, Current					1,617					1,617
Other Liabilities, Current					2,305					2,305
Liabilities, Current					6,965					6,965
Long-term Debt and Capital Lease Obligations					14,399					14,399
Liability, Defined Benefit Plan, Noncurrent					5,511					5,511
Other Liabilities, Noncurrent					994					994
Liabilities					27,869					27,869
Preferred Stock, Value, Issued					0					0
Common Stock, Value, Issued					174					174
Paid-in capital					44					44
Retained Earnings (Accumulated Deficit)					11,548					11,548
Accumulated Other Comprehensive Income (Loss), Net of Tax					(4,718)					(4,718)
Stockholders' Equity Attributable to Parent					7,048					7,048	5,259
Liabilities and Equity					34,917					34,917
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value					0					0
Revenues	0	$ 0	$ 0	$ 0	0	$ 0	$ 0	$ 0		0
General and Administrative Expense										0	0
Operating Income (Loss)	23	(6)	(6)	(6)	(32)	(8)	(9)	(9)	5	(58)	8
Interest and Debt Expense									0	0	0
Net FAS (non-service) pension benefit									535	743	752
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Other Nonoperating Income (Expense)									(2)	12	16
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									(117)	1,233	(174)
Income Tax Expense (Benefit)									(24)	359	(61)
Net Income (Loss) Attributable to Parent	$ (394)	$ 100	$ 100	$ 101	$ 525	$ 107	$ 122	$ 120	$ (93)	$ 874	$ (113)
Earnings Per Share, Basic	$ (2.29)	$ 0.58	$ 0.57	$ 0.58	$ 3.01	$ 0.62	$ 0.70	$ 0.69	$ (0.53)	$ 5.01	$ (0.63)
Weighted Average Number of Shares Outstanding, Basic										0.00	0
Earnings Per Share, Diluted	$ (2.28)	$ 0.57	$ 0.57	$ 0.58	$ 2.99	$ 0.61	$ 0.70	$ 0.68	$ (0.54)	$ 4.98	$ (0.63)
Weighted Average Number of Shares Outstanding, Diluted										0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ (874)	$ 113
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										0	0
Other, net										0	0
Other comprehensive loss, net of tax									$ 93	(874)	113
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										0	0
Accounts receivable, net					$ 0					0
Unbilled receivables, net					0					0
Inventoried costs, net					0					0
Other Assets, Current					0					0
Assets, Current					0					0
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017					0					0
Goodwill					0					0
Intangible assets, net					0					0
Deferred tax assets					0					0
Other non-current assets					0					0
Assets					0					0
Accounts Payable, Current					0					0
Employee-related Liabilities, Current					0					0
Customer Advances, Current					0					0
Other Liabilities, Current					0					0
Liabilities, Current					0					0
Long-term Debt and Capital Lease Obligations					0					0
Liability, Defined Benefit Plan, Noncurrent					0					0
Other Liabilities, Noncurrent					0					0
Liabilities					0					0
Preferred Stock, Value, Issued					0					0
Common Stock, Value, Issued					0					0
Paid-in capital					0					0
Retained Earnings (Accumulated Deficit)	$ (5,897)				(4,719)				(5,897)	(4,719)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 5,897				4,719				5,897	4,719
Stockholders' Equity Attributable to Parent					0					0	0
Liabilities and Equity					0					0
Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value					0					0
Revenues										201	198
General and Administrative Expense										57	48
Operating Income (Loss)										(53)	(68)
Interest and Debt Expense										0	0
Net FAS (non-service) pension benefit										0	0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Other Nonoperating Income (Expense)										0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										(53)	(68)
Income Tax Expense (Benefit)										(33)	(24)
Net Income (Loss) Attributable to Parent										$ (20)	$ (44)
Earnings Per Share, Basic										$ (0.11)	$ (0.25)
Weighted Average Number of Shares Outstanding, Basic										0.00	0
Earnings Per Share, Diluted										$ (0.11)	$ (0.24)
Weighted Average Number of Shares Outstanding, Diluted										0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ 0	$ 0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										0	0
Other, net										0	0
Other comprehensive loss, net of tax										0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										(20)	(44)
Accounts receivable, net					225					225
Unbilled receivables, net					318					318
Inventoried costs, net					(382)					(382)
Other Assets, Current					77					77
Assets, Current					238					238
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017					0					0
Goodwill					0					0
Intangible assets, net					0					0
Deferred tax assets					(28)					(28)
Other non-current assets					1					1
Assets					211					211
Accounts Payable, Current					0					0
Employee-related Liabilities, Current					0					0
Customer Advances, Current					144					144
Other Liabilities, Current					(17)					(17)
Liabilities, Current					127					127
Long-term Debt and Capital Lease Obligations					0					0
Liability, Defined Benefit Plan, Noncurrent					0					0
Other Liabilities, Noncurrent					0					0
Liabilities					127					127
Preferred Stock, Value, Issued					0					0
Common Stock, Value, Issued					0					0
Paid-in capital					0					0
Retained Earnings (Accumulated Deficit)					84					84
Accumulated Other Comprehensive Income (Loss), Net of Tax					0					0
Stockholders' Equity Attributable to Parent					84					84	104
Liabilities and Equity					$ 211					211
Accounting Standards Update 2017-07 [Domain] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
General and Administrative Expense										0	0
Operating Income (Loss)										30	144
Interest and Debt Expense										0	0
Net FAS (non-service) pension benefit										(44)	(141)
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Other Nonoperating Income (Expense)										14	(3)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										0	0
Income Tax Expense (Benefit)										0	0
Net Income (Loss) Attributable to Parent										$ 0	$ 0
Earnings Per Share, Basic										$ 0.00	$ 0.00
Weighted Average Number of Shares Outstanding, Basic										0.00	0
Earnings Per Share, Diluted										$ 0.00	$ 0.00
Weighted Average Number of Shares Outstanding, Diluted										0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ 0	$ 0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										0	0
Other, net										0	0
Other comprehensive loss, net of tax										0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										0	0
Product [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues									20,469	16,364	15,080
Cost of Goods and Services Sold									15,785	12,527	11,197
Product [Member] \| Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										16,038	14,738
Cost of Goods and Services Sold										12,271	11,002
Product [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										35	(5)
Product [Member] \| Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										326	342
Cost of Goods and Services Sold										239	286
Product [Member] \| Accounting Standards Update 2017-07 [Domain] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										(18)	(86)
Service [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues									9,626	9,640	9,626
Cost of Goods and Services Sold									$ 7,519	7,547	7,600
Service [Member] \| Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										9,765	9,770
Cost of Goods and Services Sold										7,578	7,729
Service [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										23	(3)
Service [Member] \| Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										(125)	(144)
Cost of Goods and Services Sold										(42)	(68)
Service [Member] \| Accounting Standards Update 2017-07 [Domain] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										$ (12)	$ (58)

Recast 2017 and 2016 Financial Information (Details 2) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 1,579	$ 11,225	$ 2,541	$ 2,319
Accounts receivable, net	1,448	1,054
Unbilled receivables, net	5,026	3,465
Inventoried costs, net	654	398
Other Assets, Current	973	445
Assets, Current	9,680	16,587
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017	6,372	4,225
Goodwill	18,672	12,455	12,450
Intangible assets, net	1,372	52
Deferred tax assets	94	447
Other non-current assets	1,463	1,362
Assets	37,653	35,128
Accounts Payable, Current	2,182	1,661
Employee-related Liabilities, Current	1,676	1,382
Customer Advances, Current	1,917	1,761
Other Liabilities, Current	2,499	2,288
Liabilities, Current	8,274	7,092
Long-term Debt and Capital Lease Obligations	13,883	14,399
Liability, Defined Benefit Plan, Noncurrent	5,755	5,511
Other Liabilities, Noncurrent	1,446	994
Liabilities	29,466	27,996
Preferred Stock, Value, Issued	0	0
Common Stock, Value, Issued	171	174
Paid-in capital	0	44
Retained Earnings (Accumulated Deficit)	8,068	6,913
Accumulated Other Comprehensive Income (Loss), Net of Tax	(52)	1
Stockholders' Equity Attributable to Parent	8,187	7,132	5,363
Liabilities and Equity	37,653	35,128
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value		0
Accounts receivable, net		0
Unbilled receivables, net		0
Inventoried costs, net		0
Other Assets, Current		0
Assets, Current		0
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017		0
Goodwill		0
Intangible assets, net		0
Deferred tax assets		0
Other non-current assets		0
Assets		0
Accounts Payable, Current		0
Employee-related Liabilities, Current		0
Customer Advances, Current		0
Other Liabilities, Current		0
Liabilities, Current		0
Long-term Debt and Capital Lease Obligations		0
Liability, Defined Benefit Plan, Noncurrent		0
Other Liabilities, Noncurrent		0
Liabilities		0
Preferred Stock, Value, Issued		0
Common Stock, Value, Issued		0
Paid-in capital		0
Retained Earnings (Accumulated Deficit)	(5,897)	(4,719)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 5,897	4,719
Stockholders' Equity Attributable to Parent		0	0
Liabilities and Equity		0
Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value		0
Accounts receivable, net		225
Unbilled receivables, net		318
Inventoried costs, net		(382)
Other Assets, Current		77
Assets, Current		238
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017		0
Goodwill		0
Intangible assets, net		0
Deferred tax assets		(28)
Other non-current assets		1
Assets		211
Accounts Payable, Current		0
Employee-related Liabilities, Current		0
Customer Advances, Current		144
Other Liabilities, Current		(17)
Liabilities, Current		127
Long-term Debt and Capital Lease Obligations		0
Liability, Defined Benefit Plan, Noncurrent		0
Other Liabilities, Noncurrent		0
Liabilities		127
Preferred Stock, Value, Issued		0
Common Stock, Value, Issued		0
Paid-in capital		0
Retained Earnings (Accumulated Deficit)		84
Accumulated Other Comprehensive Income (Loss), Net of Tax		0
Stockholders' Equity Attributable to Parent		84	$ 104
Liabilities and Equity		$ 211

Recast 2017 and 2016 Financial Information (Details 3) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization									800	475	456
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Deferred income taxes									234	985	(60)
Changes in assets and liabilities:
Stock-based compensation									86	94	93
Increase (Decrease) in Accounts Receivable									(202)	209	(46)
Unbilled receivables, net									(297)	(422)	(211)
Inventoried costs, net									37	(25)	53
Prepaid expenses and other assets									(56)	(92)	(117)
Accounts payable and other liabilities									381	570	18
Retiree benefits									(1,083)	(946)	(375)
Other, net									29	43	125
Income taxes payable, net									(258)	(157)	148
Net cash provided by operating activities									3,827	2,613	2,813
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										2,015	2,200
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization										475	456
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Deferred income taxes										603	36
Changes in assets and liabilities:
Stock-based compensation										94	93
Increase (Decrease) in Accounts Receivable										187	(55)
Unbilled receivables, net										490	516
Inventoried costs, net										(36)	15
Prepaid expenses and other assets										(81)	(110)
Accounts payable and other liabilities										539	198
Retiree benefits										(191)	393
Other, net										43	125
Income taxes payable, net										(157)	148
Net cash provided by operating activities										2,613	2,813
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent	$ (394)	$ 100	$ 100	$ 101	$ 525	$ 107	$ 122	$ 120	(93)	874	(113)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization									0	0	0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Deferred income taxes									(29)	417	(69)
Changes in assets and liabilities:
Stock-based compensation									0	0	0
Increase (Decrease) in Accounts Receivable									0	0	0
Unbilled receivables, net									0	0	0
Inventoried costs, net									0	0	0
Prepaid expenses and other assets									0	0	0
Accounts payable and other liabilities									0	0	0
Retiree benefits									(533)	(755)	(768)
Other, net									0	0	0
Income taxes payable, net									0	0	0
Net cash provided by operating activities									$ 0	0	0
Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										(20)	(44)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization										0	0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Deferred income taxes										(35)	(27)
Changes in assets and liabilities:
Stock-based compensation										0	0
Increase (Decrease) in Accounts Receivable										22	9
Unbilled receivables, net										(68)	(305)
Inventoried costs, net										11	38
Prepaid expenses and other assets										(11)	(7)
Accounts payable and other liabilities										31	(180)
Retiree benefits										0	0
Other, net										0	0
Income taxes payable, net										0	0
Net cash provided by operating activities										0	0
Accounting Standards Update 2017-07 [Domain] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										0	0
Adjustments to reconcile to net cash provided by operating activities:
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										$ 0	$ 0

Recast 2017 and 2016 Financial Information (Details 4) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	$ 8,187				$ 7,132				$ 8,187	$ 7,132	$ 5,363
Net Income (Loss) Attributable to Parent	356	$ 1,244	$ 789	$ 840	672	$ 750	$ 677	$ 770	3,229	2,869	2,043
Other comprehensive loss, net of tax									(74)	(46)	(113)
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					7,048					7,048	5,259
Net Income (Loss) Attributable to Parent										2,015	2,200
Other comprehensive loss, net of tax										828	(226)
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					0					0	0
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures									0
Stock Repurchased and Retired During Period, Value									0
Net Income (Loss) Attributable to Parent	(394)	$ 100	$ 100	$ 101	525	$ 107	$ 122	$ 120	(93)	874	(113)
Dividends, Common Stock									0
Other comprehensive loss, net of tax									93	(874)	113
Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					84					84	104
Net Income (Loss) Attributable to Parent										(20)	(44)
Other comprehensive loss, net of tax										0	0
Accounting Standards Update 2017-07 [Domain] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Income (Loss) Attributable to Parent										0	0
Other comprehensive loss, net of tax										0	0
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	8,068				6,913				8,068	6,913	5,141	$ 5,329
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures									(6)	(39)	(50)
Stock Repurchased and Retired During Period, Value									(1,225)	(371)	(1,548)
Net Income (Loss) Attributable to Parent										2,869	2,043
Dividends, Common Stock									(822)	(687)	(633)
Retained Earnings [Member] \| Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					11,548					11,548	10,630	10,661
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures										(39)	(50)
Stock Repurchased and Retired During Period, Value										(371)	(1,548)
Net Income (Loss) Attributable to Parent										2,015	2,200
Dividends, Common Stock										(687)	(633)
Retained Earnings [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	(5,897)				(4,719)				(5,897)	(4,719)	(5,593)	(5,480)
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures										0	0
Stock Repurchased and Retired During Period, Value										0	0
Net Income (Loss) Attributable to Parent										874	(113)
Dividends, Common Stock										0	0
Retained Earnings [Member] \| Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					84					84	104	148
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures										0	0
Stock Repurchased and Retired During Period, Value										0	0
Net Income (Loss) Attributable to Parent										(20)	(44)
Dividends, Common Stock										0	0
AOCI Attributable to Parent [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	(52)				1				(52)	1	47	160
Other comprehensive loss, net of tax									(74)	(46)	(113)
AOCI Attributable to Parent [Member] \| Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					(4,718)					(4,718)	(5,546)	(5,320)
Other comprehensive loss, net of tax										828	(226)
AOCI Attributable to Parent [Member] \| Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] \| Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent	$ 5,897				4,719				$ 5,897	4,719	5,593	5,480
Other comprehensive loss, net of tax										(874)	113
AOCI Attributable to Parent [Member] \| Accounting Standards Update 2014-09 [Member] \| Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity Attributable to Parent					$ 0					0	0	$ 0
Other comprehensive loss, net of tax										$ 0	$ 0