General Dynamics (GD) 10-K 13 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 27, 2019	Jul. 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	GENERAL DYNAMICS CORPORATION
Entity Central Index Key	40,533
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		288,235,928
Trading Symbol	GD
Entity Public Float			$ 48,890,306,362
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false

Consolidated Statement of Earni

Consolidated Statement of Earnings - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Revenue	$ 36,193	$ 30,973	$ 30,561
Operating costs and expenses:
Cost of sales	(29,478)	(24,731)	(24,896)
General and administrative (G&A)	(2,258)	(2,006)	(1,921)
Operating costs and expenses, Total	(31,736)	(26,737)	(26,817)
Operating earnings	4,457	4,236	3,744
Interest, net	(356)	(103)	(91)
Other, net	(16)	(56)	3
Earnings from continuing operations before income tax	4,085	4,077	3,656
Provision for income tax, net	(727)	(1,165)	(977)
Earnings from continuing operations	3,358	2,912	2,679
Discontinued operations, net of tax provision of $13 in 2018 and tax benefit of $51 in 2016	(13)	0	(107)
Net earnings	$ 3,345	$ 2,912	$ 2,572
Basic:
Continuing operations	$ 11.37	$ 9.73	$ 8.79
Discontinued operations	(0.04)	0	(0.35)
Net earnings	11.33	9.73	8.44
Diluted:
Continuing operations	11.22	9.56	8.64
Discontinued operations	(0.04)	0	(0.35)
Net earnings	$ 11.18	$ 9.56	$ 8.29
Products
Revenue:
Revenue	$ 20,149	$ 19,016	$ 19,010
Operating costs and expenses:
Cost of sales	(15,894)	(14,773)	(15,155)
Services
Revenue:
Revenue	16,044	11,957	11,551
Operating costs and expenses:
Cost of sales	$ (13,584)	$ (9,958)	$ (9,741)

Consolidated Statement of Ear_2

Consolidated Statement of Earnings (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Discontinued operations, tax provision (benefit)	$ 13	$ 0	$ (51)

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 3,345	$ 2,912	$ 2,572
Gains on cash flow hedges	36	341	191
Unrealized gains (losses) on marketable securities	0	9	(9)
Foreign currency translation adjustments	(300)	348	(112)
Change in retirement plans’ funded status	(61)	20	(192)
Other comprehensive (loss) income, pretax	(325)	718	(122)
Benefit (provision) for income tax, net	5	(151)	18
Other comprehensive (loss) income, net of tax	(320)	567	(104)
Comprehensive income	$ 3,025	$ 3,479	$ 2,468

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and equivalents	$ 963	$ 2,983
Accounts receivable	3,759	3,617
Unbilled receivables	6,576	5,240
Inventories	5,977	5,303
Other current assets	914	1,185
Total current assets	18,189	18,328
Noncurrent assets:
Property, plant and equipment, net	4,348	3,517
Intangible assets, net	2,585	702
Goodwill	19,594	11,914
Other assets	692	585
Total noncurrent assets	27,219	16,718
Total assets	45,408	35,046
Current liabilities:
Short-term debt and current portion of long-term debt	973	2
Accounts payable	3,179	3,207
Customer advances and deposits	7,270	6,992
Other current liabilities	3,317	2,898
Total current liabilities	14,739	13,099
Noncurrent liabilities:
Long-term debt	11,444	3,980
Other liabilities	7,493	6,532
Commitments and contingencies (see Note O)
Total noncurrent liabilities	18,937	10,512
Shareholders’ equity:
Common stock	482	482
Surplus	2,946	2,872
Retained earnings	29,326	26,444
Treasury stock	(17,244)	(15,543)
Accumulated other comprehensive loss	(3,778)	(2,820)
Total shareholders’ equity	11,732	11,435
Total liabilities and shareholders’ equity	$ 45,408	$ 35,046

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities - continuing operations:
Net earnings		$ 3,345	$ 2,912	$ 2,572
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation of property, plant and equipment		493	362	365
Amortization of intangible assets		270	79	88
Equity-based compensation expense		140	123	95
Deferred income tax (benefit) provision		(3)	401	184
Discontinued operations, net of tax		13	0	107
(Increase) decrease in assets, net of effects of business acquisitions:
Accounts receivable		417	(195)	(122)
Unbilled receivables		(800)	(987)	(1,048)
Inventories		(591)	(182)	(377)
Other current assets		310	207	315
Increase (decrease) in liabilities, net of effects of business acquisitions:
Accounts payable		(197)	657	567
Customer advances and deposits		36	264	(305)
Other, net		(285)	235	(278)
Net cash provided by operating activities	[1]	3,148	3,876	2,163
Cash flows from investing activities:
Business acquisitions, net of cash acquired		(10,099)	(399)	(58)
Capital expenditures		(690)	(428)	(392)
Proceeds from sales of assets		562	50	9
Other, net		(7)	(11)	50
Net cash used by investing activities		(10,234)	(788)	(391)
Cash flows from financing activities:
Proceeds from notes		6,461	985	992
Purchases of common stock		(1,769)	(1,558)	(1,996)
Dividends paid		(1,075)	(986)	(911)
Proceeds from commercial paper, net		851	0	0
Repayment of CSRA accounts receivable purchase agreement		(450)	0	0
Proceeds from stock option exercises		136	163	292
Repayment of fixed-rate notes		0	(900)	(500)
Other, net		(68)	(103)	(46)
Net cash provided (used) by financing activities		5,086	(2,399)	(2,169)
Net cash used by discontinued operations		(20)	(40)	(54)
Net (decrease) increase in cash and equivalents		(2,020)	649	(451)
Cash and equivalents at beginning of year		2,983	2,334	2,785
Cash and equivalents at end of year		963	2,983	2,334
LIBOR
Cash flows from financing activities:
Proceeds from notes		$ 1,000	$ 0	$ 0
[1]	* Continuing operations only.

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity - USD ($) $ in Millions		Total	Common Stock	Common Stock Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2015		$ 10,440	$ 482	$ 2,730	$ 22,903	$ (12,392)	$ (3,283)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings		2,572			2,572
Cash dividends declared		(932)			(932)
Equity-based awards		356		89		267
Shares purchased		(2,031)				(2,031)
Other comprehensive income (loss)		(104)					(104)
Ending Balance at Dec. 31, 2016		10,301	482	2,819	24,543	(14,156)	(3,387)
Cumulative-effects adjustments	[1]	(3)			(3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings		2,912			2,912
Cash dividends declared		(1,008)			(1,008)
Equity-based awards		199		53		146
Shares purchased		(1,533)				(1,533)
Other comprehensive income (loss)		567					567
Ending Balance at Dec. 31, 2017		11,435	482	2,872	26,444	(15,543)	(2,820)
Cumulative-effects adjustments		0			638		(638)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings		3,345			3,345
Cash dividends declared		(1,101)			(1,101)
Equity-based awards		179		74		105
Shares purchased		(1,806)				(1,806)
Other comprehensive income (loss)		(320)					(320)
Ending Balance at Dec. 31, 2018		$ 11,732	$ 482	$ 2,946	$ 29,326	$ (17,244)	$ (3,778)
[1]	Reflects the cumulative effect of Accounting Standards Update (ASU) 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory, which we adopted on January 1, 2017.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization. General Dynamics is a global aerospace and defense company that offers a broad portfolio of products and services in business aviation; combat vehicles, weapons systems and munitions; information technology (IT) services; C4ISR (command, control, communications, computers, intelligence, surveillance and reconnaissance) solutions; and shipbuilding and ship repair. On April 3, 2018 , we completed our acquisition of CSRA Inc. (CSRA). See Note B for further discussion of the acquisition. Concurrent with the acquisition, for segment reporting purposes, we reorganized our Information Systems and Technology operating segment into two separate segments: Information Technology and Mission Systems. Our company now has five operating segments: Aerospace, Combat Systems, Information Technology, Mission Systems and Marine Systems. The latter four segments we collectively refer to as our defense segments. Prior-period segment information has been restated for this change. Basis of Consolidation and Classification. The Consolidated Financial Statements include the accounts of General Dynamics Corporation and our wholly owned and majority-owned subsidiaries. We eliminate all inter-company balances and transactions in the Consolidated Financial Statements. Some prior-year amounts have been reclassified among financial statement accounts or disclosures to conform to the current-year presentation. Consistent with industry practice, we classify assets and liabilities related to long-term contracts as current, even though some of these amounts may not be realized within one year. Further discussion of our significant accounting policies is contained in the other notes to these financial statements. Use of Estimates. The nature of our business requires that we make estimates and assumptions in accordance with U.S. generally accepted accounting principles (GAAP). These estimates and assumptions affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenue and expenses during the reporting period . We base our estimates on historical experience, currently available information and various other assumptions that we believe are reasonable under the circumstances . Actual results could differ from these estimates. Discontinued Operations, Net of Tax. Concurrent with the acquisition of CSRA, we were required by a government customer to dispose of certain CSRA operations to address an organizational conflict of interest with respect to services provided to the customer. In 2018, we sold these operations. In accordance with GAAP, the sale did not result in a gain for financial reporting purposes. However, the sale generated a taxable gain, resulting in tax expense of $13 . In 2013, we settled litigation with the U.S. Navy related to the terminated A-12 aircraft contract in the company’s former tactical military aircraft business. In connection with the settlement, we released some rights to reimbursement of costs on ships under contract at our Bath, Maine, shipyard. As we progressed through the shipbuilding process, we determined that the cost associated with this settlement was greater than anticipated. Therefore, in 2016, we recognized an $84 loss, net of tax, to adjust the previously recognized settlement value. In addition, we recognized $23 of losses, net of tax, in 2016 related to other former operations of the company. Research and Development Expenses. Company-sponsored research and development (R&D) expenses, including product development costs, were $502 in 2018 , $521 in 2017 and $418 in 2016 . The R&D expenses in 2018 and 2017 reflected ongoing product-development efforts in the Aerospace segment as we progressed with the certification of our two newest Gulfstream aircraft models, the G500 and G600. R&D expenses are included in operating costs and expenses in the Consolidated Statement of Earnings in the period in which they are incurred. Customer-sponsored R&D expenses are charged directly to the related contracts. The Aerospace segment has cost-sharing arrangements with some of its suppliers that enhance the segment’s internal development capabilities and offset a portion of the financial cost associated with the segment’s product development efforts. These arrangements explicitly state that supplier contributions are for reimbursements of costs we incur in the development of new aircraft models and technologies, and we retain substantial rights in the products developed under these arrangements. We record amounts received from these cost-sharing arrangements as a reduction of R&D expenses. We have no obligation to refund any amounts received under the agreements regardless of the outcome of the development efforts. Under the typical terms of an agreement, payments received from suppliers for their share of the costs are based on milestones and are recognized as received. Our policy is to defer payments in excess of the costs we have incurred. Interest, Net. Net interest expense consisted of the following: Year Ended December 31 2018 2017 2016 Interest expense $ 374 $ 117 $ 99 Interest income (18 ) (14 ) (8 ) Interest expense, net $ 356 $ 103 $ 91 The increase in 2018 is due primarily to the impact of financing the CSRA acquisition, including the issuance of $7.5 billion of fixed- and floating-rate notes in the second quarter of 2018. See Note K for additional information regarding our debt obligations, including interest rates. Cash and Equivalents and Investments in Debt and Equity Securities. We consider securities with a maturity of three months or less to be cash equivalents. Our cash balances are invested primarily in time deposits rated A-/A3 or higher. Our investments in other securities are included in other current and noncurrent assets on the Consolidated Balance Sheet (see Note E). We report our equity securities at fair value with subsequent changes in fair value recognized in net earnings. We report our available-for-sale debt securities at fair value with unrealized gains and losses recognized as a component of other comprehensive income in the Consolidated Statement of Comprehensive Income. We had no trading or held-to-maturity debt securities on December 31, 2018 or 2017 . Other Contract Costs. Other contract costs represent amounts that are not currently allocable to government contracts, such as a portion of our estimated workers’ compensation obligations, other insurance-related assessments, pension and other post-retirement benefits, and environmental expenses. These costs will become allocable to contracts generally after they are paid. We expect to recover these costs through ongoing business, including existing backlog and probable follow-on contracts. If the backlog in the future does not support the continued deferral of these costs, the profitability of our remaining contracts could be adversely affected. Other contract costs on December 31, 2018 and 2017 , were $135 and $448 , respectively, and are included in other current assets on the Consolidated Balance Sheet . Long-lived Assets and Goodwill. We review long-lived assets, including intangible assets subject to amortization, for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. We assess the recoverability of the carrying value of assets held for use based on a review of undiscounted projected cash flows. Impairment losses, where identified, are measured as the excess of the carrying value of the long-lived asset over its estimated fair value as determined by discounted projected cash flows. Concurrent with the acquisition of CSRA in April 2018, we reorganized our Information Systems and Technology operating segment in accordance with the nature of the segment’s products and services into the Information Technology and Mission Systems segments. This reorganization similarly changed the composition of our reporting units. Accordingly, goodwill of the Information Systems and Technology reporting unit was reassigned to the Information Technology and Mission Systems reporting units using a relative fair value allocation approach as of the date of the reorganization. We review goodwill for impairment annually or when circumstances indicate that the likelihood of an impairment is greater than 50%. Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired in a business combination. The test for goodwill impairment is a two-step process to first identify potential goodwill impairment for each reporting unit by comparing the fair value of each of our reporting units to its respective carrying value and then, if necessary, measure the amount of the impairment loss. Our reporting units are consistent with our operating segments in Note R . We estimate the fair value of our reporting units based primarily on the discounted projected cash flows of the underlying operations. We completed the required annual goodwill impairment test as of December 31, 2018 . The results of the first-step test indicated that, for each of our reporting units, no impairment existed. The estimated fair value of each of our reporting units was substantially in excess of its respective carrying value as of December 31, 2018 , with the exception of our Information Technology reporting unit . The estimated fair value of the Information Technology reporting unit exceeded its carrying value as of December 31, 2018 , by slightly more than 5% . This is due to the significant size of the CSRA acquisition relative to the newly formed Information Technology reporting unit and its recent acquisition date. Given that the net book value of this business was recorded at its fair value during the current reporting period, the reporting unit’s carrying value, by default, closely approximates its fair value at year end. As the carrying value and fair value of the Information Technology reporting unit are closely aligned, a material change in the fair value or carrying value would put the reporting unit at risk of goodwill impairment. For example, our ability to realize synergies from the acquisition of CSRA and the level of funding in the U.S. government budget for contracts in our portfolio are key assumptions in our projections of revenue, earnings and cash flows. If our actual experience in future years falls significantly below our current projections, the fair value of the reporting unit could be negatively impacted. Similarly, an increase in interest rates would lower our discounted cash flows and negatively impact the fair value of the reporting unit. We believe the projections and assumptions we used in estimating fair value are reasonable, but it is possible they could change, impacting our fair value estimate, or the carrying value could change. For a summary of our goodwill by reporting unit, see Note B. Accounting Standards Updates. On January 1, 2018, we adopted the following accounting standards issued by the Financial Accounting Standards Board (FASB): • ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Specific to our business, ASU 2016-01 requires equity investments to be measured at fair value with changes in fair value recognized in net income. The ASU eliminates the available-for-sale classification for equity investments that recognized changes in fair value as a component of other comprehensive income. We adopted the standard on a modified retrospective basis on January 1, 2018, and recognized the cumulative effect as a $24 increase to retained earnings on the date of adoption. • ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. ASU 2016-15 is intended to reduce diversity in practice in how certain cash receipts and cash payments are presented and classified in the Consolidated Statement of Cash Flows by providing guidance on eight specific cash flow issues. We adopted the standard retrospectively on January 1, 2018. The adoption of the ASU did not have a material effect on our cash flows in 2017 and 2016. • ASU 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 the service cost component of net retirement benefit cost to be reported separately from the other components of net retirement benefit cost in the Consolidated Statement of Earnings. We adopted the standard retrospectively on January 1, 2018. Our restated operating earnings increased $59 and $10 in 2017 and 2016 , respectively, due to the reclassification of the non-service cost components of net benefit cost. Other income decreased by the same amount, with no impact to net earnings. • ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. ASU 2018-02 allows the reclassification from accumulated other comprehensive income to retained earnings of stranded tax effects resulting from the implementation of the Tax Cuts and Jobs Act (tax reform) enacted on December 22, 2017. We adopted the standard on January 1, 2018, and recognized a $614 increase to retained earnings on the date of adoption. There are several other accounting standards that have been issued by the FASB but are not effective until after December 31, 2018, including the following: • ASU 2016-02, Leases (Topic 842). ASU 2016-02 requires the recognition of lease rights and obligations as assets and liabilities on the balance sheet. Previously, lessees were not required to recognize on the balance sheet assets and liabilities arising from operating leases. The ASU also requires disclosure of key information about leasing arrangements. ASU 2016-02 is effective on January 1, 2019, using a modified retrospective method of adoption as of January 1, 2017. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements, which provides an alternative transition method of adoption, permitting the recognition of a cumulative-effect adjustment to retained earnings on the date of adoption in lieu of retrospective adoption. We are adopting the standard effective January 1, 2019, using the alternative transition method provided by ASU 2018-11. In order to adopt the new standard, we developed a comprehensive project plan and established cross-functional project teams to guide the implementation. The project plan included implementing a third-party software solution to facilitate the consolidation of our leases for reporting purposes, reviewing all forms of leases, performing a completeness assessment of our lease population, analyzing the optional practical expedients available in the new standard, and updating our business processes, systems and controls to meet the requirements of the new standard. The new standard provides several optional practical expedients for use in transition. We have elected to use what the FASB has deemed the “package of practical expedients,” which allows us not to reassess our previous conclusions about lease identification, lease classification and the accounting treatment for initial direct costs. We have not elected the practical expedients pertaining to the use of hindsight and land easements. The ASU also provides several optional practical expedients for the ongoing accounting for leases. We have elected the short-term lease recognition exemption for all leases that qualify, meaning that for these leases, we will not recognize right-of-use (ROU) assets or lease liabilities on our Consolidated Balance Sheet. Additionally, we have elected to use the practical expedient to not separate lease and non-lease components for leases of real estate, meaning that for these leases, the non-lease components are included in the associated ROU asset and lease liability balances on our Consolidated Balance Sheet. The most significant effects of the standard on our Consolidated Financial Statements are (1) the recognition of new ROU assets and lease liabilities on our Consolidated Balance Sheet for our operating leases, and (2) significant new disclosures about our leasing activities. We expect to recognize operating lease liabilities ranging from $1.2 to $1.6 billion , with corresponding ROU assets of the same amount based on the present value of the remaining lease payments over the lease term. The new standard is not expected to have a material impact on our results of operations or cash flows. • ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. ASU 2017-12 is intended to simplify hedge accounting by better aligning an entity’s financial reporting for hedging relationships with its risk management activities through the expansion of the types of financial and nonfinancial hedging strategies that are eligible for hedge accounting. The ASU also simplifies the application of the hedge accounting guidance, including eliminating the requirement to separately measure and report hedge ineffectiveness. For cash flow hedges existing at the adoption date, the standard requires adoption on a modified retrospective basis with a cumulative-effect adjustment to the Consolidated Balance Sheet as of the beginning of the year of adoption. The amendments to presentation guidance and disclosure requirements are required to be adopted prospectively. We adopted the standard on January 1, 2019. The adoption of the ASU did not have a material effect on our results of operations, financial condition or cash flows.

Acquisitions and Divestitures,

Acquisitions and Divestitures, Goodwill, and Intangible Assets	12 Months Ended
	Dec. 31, 2018
Business Combinations, Goodwill and Intangible Assets Disclosure [Abstract]
Acquisitions and Divestitures, Goodwill, and Intangible Assets	ACQUISITIONS AND DIVESTITURES, GOODWILL, AND INTANGIBLE ASSETS CSRA Acquisition On April 3, 2018 , we acquired 100% of the outstanding shares of CSRA for $41.25 per share in cash plus the assumption of outstanding net debt. CSRA has been combined with General Dynamics Information Technology (GDIT) to create a premier provider of IT solutions to the defense, intelligence and federal civilian markets. Except where otherwise noted in the Notes to the Consolidated Financial Statements, changes in balances and activity were generally driven by the CSRA acquisition. Purchase Price and Fair Value of Net Assets Acquired. The cash purchase price totaled $9.7 billion and consisted of the following: CSRA shares outstanding (in millions) 165.4 Cash consideration per CSRA share $ 41.25 Cash paid to purchase outstanding CSRA shares $ 6,825 Cash paid to extinguish CSRA debt 2,846 Cash settlement of outstanding CSRA stock options and restricted stock units 78 Total purchase price $ 9,749 The following table summarizes the preliminary allocation of the purchase price to the estimated fair values of the assets acquired and liabilities assumed on the acquisition date, with the excess recorded as goodwill: Cash and equivalents $ 45 Accounts receivable 154 Unbilled receivables 510 Other current assets 301 Property, plant and equipment, net 673 Intangible assets, net 2,066 Goodwill 7,859 Other noncurrent assets 20 Total assets $ 11,628 Accounts payable $ (139 ) Customer advances and deposits (151 ) Current capital lease obligation (51 ) Other current liabilities (404 ) Noncurrent capital lease obligation (207 ) Noncurrent deferred tax liability (376 ) Other noncurrent liabilities (551 ) Total liabilities $ (1,879 ) Net assets acquired $ 9,749 We have continued to obtain information to refine the estimated fair values. The additional information obtained during the quarter did not result in any material adjustments. However, these provisional amounts are subject to change as we continue to evaluate information required to complete the valuations throughout the measurement period, which will extend into the second quarter of 2019 . We have valued $2.1 billion of acquired intangible assets, which consist of acquired backlog and probable follow-on work and associated customer relationships (contract and program intangible assets), with a weighted-average life of 17 years. The intangible assets will be amortized using an accelerated method, which approximates the pattern of how the economic benefit is expected to be used. Under this method, approximately 50% of the aggregate value of the intangible assets will be amortized within six years. Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired, and is attributable primarily to expected synergies, economies of scale and the assembled workforce of CSRA. Approximately $490 of this goodwill is pre-acquisition goodwill deductible for income tax purposes over its remaining tax life. CSRA’s operating results have been included with our reported results since the acquisition date. As we immediately began integrating CSRA with GDIT following the acquisition, it is becoming increasingly difficult to separate the results of legacy CSRA from those of the combined entity. Approximately $3.7 billion of revenue, $400 of operating earnings and $430 of pretax earnings from legacy CSRA were included in our Consolidated Statement of Earnings in 2018 . These amounts exclude amortization of intangible assets and acquisition financing. In addition, we have recognized approximately $75 of one-time, acquisition-related costs, reported in operating costs and expenses and other income (expense) in the Consolidated Statement of Earnings. Pro Forma Information (Unaudited). The following pro forma information presents our consolidated revenue and earnings from continuing operations as if the acquisition of CSRA and the related financing transactions had occurred on January 1, 2017 : Year Ended December 31 2018 2017 Revenue $ 37,534 $ 35,828 Earnings from continuing operations 3,390 2,982 Diluted earnings per share from continuing operations $ 11.33 $ 9.79 The pro forma information was prepared by combining our reported historical results with the historical results of CSRA for the pre-acquisition periods. In addition, the reported historical amounts were adjusted for the following items, net of associated tax effects: • The impact of acquisition financing. • The removal of certain CSRA operations we were required by a government customer to dispose of to address an organizational conflict of interest with respect to services provided to the customer. We completed the sale of these operations in 2018 . • The removal of CSRA’s historical pre-acquisition intangible asset amortization expense and debt-related interest expense. • The impact of intangible asset amortization expense assuming our current estimate of fair value was applied on January 1, 2017 . • The payment of acquisition-related costs assuming they were incurred on January 1, 2017 . The pro forma information is based on the preliminary amounts allocated to the estimated fair value of net assets acquired and may be revised as the provisional amounts change. The pro forma information does not reflect the realization of expected cost savings or synergies from the acquisition, and does not reflect what our combined results of operations would have been had the acquisition occurred on January 1, 2017 . Other Acquisitions and Divestitures In addition to the acquisition of CSRA, we acquired five businesses in 2018 for an aggregate of approximately $400 : • Hawker Pacific, a leading provider of integrated aviation solutions across Asia Pacific and the Middle East, and two fixed-base operation (FBO) businesses in our Aerospace segment; • a maintenance and service provider for the German Army and other international customers in our Combat Systems segment; and • a provider of specialized transmitters and receivers in our Mission Systems segment. In 2017 , we acquired four businesses for an aggregate of approximately $400 : • an FBO in our Aerospace segment; • a provider of mission-critical support services in our Information Technology segment; and • a manufacturer of electronics and communications products and a manufacturer of signal distribution products in our Mission Systems segment. In 2016 , we acquired two businesses for an aggregate of approximately $60 : • an aircraft management and charter services provider in our Aerospace segment; and • a manufacturer of unmanned underwater vehicles in our Mission Systems segment. The operating results of these acquisitions have been included with our reported results since the respective closing dates. The purchase prices of the acquisitions have been allocated to the estimated fair value of net tangible and intangible assets acquired, with any excess purchase price recorded as goodwill. In 2018 , we completed the sale of three businesses in our Information Technology segment: • a commercial health products business ; • certain CSRA operations we were required by a government customer to dispose of to address an organizational conflict of interest with respect to services provided to the customer ; and • a public-facing contact-center business . Goodwill The changes in the carrying amount of goodwill by reporting unit were as follows: Aerospace Combat Systems Information Systems and Technology Information Technology Mission Systems Marine Systems Total Goodwill December 31, 2016 (a) $ 2,537 $ 2,598 $ 6,013 $ — $ — $ 297 $ 11,445 Acquisitions/ divestitures (b) 28 — 268 — — — 296 Other (c) 73 79 21 — — — 173 December 31, 2017 (a) 2,638 2,677 6,302 — — 297 11,914 Acquisitions/ divestitures (b) — — 16 — — — 16 Other (c) 40 (14 ) (1 ) — — — 25 April 1, 2018 (a) 2,678 2,663 6,317 — — 297 11,955 Change in reporting unit composition (d) — — (6,317 ) 2,076 4,241 — — Acquisitions/ divestitures (b) 183 30 — 7,601 7 — 7,821 Other (c) (48 ) (60 ) — (55 ) (19 ) — (182 ) December 31, 2018 (e) $ 2,813 $ 2,633 $ — $ 9,622 $ 4,229 $ 297 $ 19,594 (a) Goodwill in the Information Systems and Technology reporting unit is net of $1.9 billion of accumulated impairment losses. (b) Includes adjustments during the purchase price allocation period. Activity in the first quarter of 2018 and the nine-month period ended December 31, 2018 , also includes an allocation of goodwill associated with the sale of the commercial health products business and an allocation of goodwill associated with the sale of a public-facing contact-center business, respectively, as discussed above. (c) Consists primarily of adjustments for foreign currency translation. Activity in the nine-month period ended December 31, 2018 , also includes an allocation of goodwill in our Information Technology reporting unit associated with certain operations classified as held for sale on the Consolidated Balance Sheet on December 31, 2018 . (d) Concurrent with the acquisition of CSRA, we reorganized our Information Systems and Technology operating segment into the Information Technology and Mission Systems segments. See Note A for further discussion of the segment reorganization. This reorganization similarly changed the composition of our reporting units. Accordingly, goodwill of the Information Systems and Technology reporting unit was reassigned to the Information Technology and Mission Systems reporting units using a relative fair value allocation approach as of the date of the reorganization. (e) Goodwill in the Information Technology and Mission Systems reporting units is net of $536 and $1.3 billion of accumulated impairment losses, respectively. Intangible Assets Intangible assets consisted of the following: Gross Carrying Amount (a) Accumulated Amortization Net Carrying Amount Gross Carrying Amount (a) Accumulated Amortization Net Carrying Amount December 31 2018 2017 Contract and program intangible assets (b) $ 3,771 $ (1,531 ) $ 2,240 $ 1,684 $ (1,320 ) $ 364 Trade names and trademarks 469 (177 ) 292 465 (160 ) 305 Technology and software 165 (116 ) 49 137 (105 ) 32 Other intangible assets 159 (155 ) 4 155 (154 ) 1 Total intangible assets $ 4,564 $ (1,979 ) $ 2,585 $ 2,441 $ (1,739 ) $ 702 (a) Change in gross carrying amounts consists primarily of adjustments for acquired intangible assets and foreign currency translation. (b) Consists of acquired backlog and probable follow-on work and associated customer relationships. We did not recognize any impairments of our intangible assets in 2018 , 2017 or 2016 . The amortization lives (in years) of our intangible assets on December 31, 2018 , were as follows: Intangible Asset Range of Amortization Life Contract and program intangible assets 7-30 Trade names and trademarks 30 Technology and software 5-20 Other intangible assets 2-7 Amortization expense is included in operating costs and expenses in the Consolidated Statement of Earnings. Amortization expense was $270 in 2018 , $79 in 2017 and $88 in 2016 . We expect to record annual amortization expense over the next five years as follows: Year Ended December 31 Amortization Expense 2019 $ 280 2020 265 2021 217 2022 192 2023 175

Revenue

Revenue	12 Months Ended
	Dec. 31, 2018
Revenue Recognition [Abstract]
Revenue	REVENUE The majority of our revenue is derived from long-term contracts and programs that can span several years. We account for revenue in accordance with Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers. Performance Obligations. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in ASC Topic 606 . A contract’s transaction price is allocated to each distinct performance obligation within that contract and recognized as revenue when, or as, the performance obligation is satisfied. The majority of our contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and is, therefore, not distinct. Some of our contracts have multiple performance obligations, most commonly due to the contract covering multiple phases of the product lifecycle (development, production, maintenance and support). For contracts with multiple performance obligations, we allocate the contract’s transaction price to each performance obligation using our best estimate of the standalone selling price of each distinct good or service in the contract. The primary method used to estimate standalone selling price is the expected cost plus a margin approach, under which we forecast our expected costs of satisfying a performance obligation and then add an appropriate margin for that distinct good or service. Contract modifications are routine in the performance of our contracts. Contracts are often modified to account for changes in contract specifications or requirements. In most instances, contract modifications are for goods or services that are not distinct and, therefore, are accounted for as part of the existing contract. Our performance obligations are satisfied over time as work progresses or at a point in time. Revenue from products and services transferred to customers over time accounted for 74% of our revenue in 2018 , 71% in 2017 and 72% in 2016 . Substantially all of our revenue in the defense segments is recognized over time, because control is transferred continuously to our customers. Typically, revenue is recognized over time using costs incurred to date relative to total estimated costs at completion to measure progress toward satisfying our performance obligations. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contract costs include labor, material, overhead and, when appropriate, G&A expenses. Revenue from goods and services transferred to customers at a point in time accounted for 26% of our revenue in 2018 , 29% in 2017 and 28% in 2016 . The majority of our revenue recognized at a point in time is for the manufacture of business-jet aircraft in our Aerospace segment. Revenue on these contracts is recognized when the customer obtains control of the asset, which is generally upon delivery and acceptance by the customer of the fully outfitted aircraft. On December 31, 2018 , we had $67.9 billion of remaining performance obligations, which we also refer to as total backlog. We expect to recognize approximately 45% of our remaining performance obligations as revenue in 2019, an additional 35% by 2021 and the balance thereafter. On December 31, 2017 , we had $63.2 billion of remaining performance obligations, at which time we expected to recognize approximately 40% of these remaining performance obligations as revenue in 2018, an additional 40% by year-end 2020 and the balance thereafter. Contract Estimates. Accounting for long-term contracts and programs involves the use of various techniques to estimate total contract revenue and costs. For long-term contracts, we estimate the profit on a contract as the difference between the total estimated revenue and expected costs to complete a contract and recognize that profit over the life of the contract. Contract estimates are based on various assumptions to project the outcome of future events that often span several years. These assumptions include labor productivity and availability; the complexity of the work to be performed; the cost and availability of materials; the performance of subcontractors; and the availability and timing of funding from the customer. The nature of our contracts gives rise to several types of variable consideration, including claims and award and incentive fees. We include in our contract estimates additional revenue for submitted contract modifications or claims against the customer when we believe we have an enforceable right to the modification or claim, the amount can be estimated reliably and its realization is probable. In evaluating these criteria, we consider the contractual/legal basis for the claim, the cause of any additional costs incurred, the reasonableness of those costs and the objective evidence available to support the claim. We include award or incentive fees in the estimated transaction price when there is a basis to reasonably estimate the amount of the fee. These estimates are based on historical award experience, anticipated performance and our best judgment at the time. Because of our certainty in estimating these amounts, they are included in the transaction price of our contracts and the associated remaining performance obligations. As a significant change in one or more of these estimates could affect the profitability of our contracts, we review and update our contract-related estimates regularly. We recognize adjustments in estimated profit on contracts under the cumulative catch-up method. Under this method, the impact of the adjustment on profit recorded to date on a contract is recognized in the period the adjustment is identified. Revenue and profit in future periods of contract performance are recognized using the adjusted estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, we recognize the total loss in the period it is identified. The impact of adjustments in contract estimates on our operating earnings can be reflected in either operating costs and expenses or revenue. The aggregate impact of adjustments in contract estimates increased our revenue, operating earnings and diluted earnings per share as follows: Year Ended December 31 2018 2017 2016 Revenue $ 377 $ 292 $ 95 Operating earnings 345 323 16 Diluted earnings per share $ 0.91 $ 0.69 $ 0.03 While no adjustment on any one contract was material to our Consolidated Financial Statements in 2018 , 2017 or 2016 , the amount in 2016 was negatively impacted by a loss on the design and development phase of the AJAX program in our Combat Systems segment and cost growth associated with the restart of the Navy’s DDG-51 program in our Marine Systems segment. Revenue by Category. Our portfolio of products and services consists of approximately 11,000 active contracts. The following series of tables presents our revenue disaggregated by several categories. Revenue by major products and services was as follows: Year Ended December 31 2018 2017 2016 Aircraft manufacturing and completions $ 6,226 $ 6,320 $ 6,074 Aircraft services 2,096 1,743 1,625 Pre-owned aircraft 133 66 116 Total Aerospace 8,455 8,129 7,815 Military vehicles 4,027 3,731 3,378 Weapons systems, armament and munitions 1,798 1,633 1,517 Engineering and other services 416 585 635 Total Combat Systems 6,241 5,949 5,530 IT services 8,269 4,410 4,428 Total Information Technology 8,269 4,410 4,428 C4ISR solutions 4,726 4,481 4,716 Total Mission Systems 4,726 4,481 4,716 Nuclear-powered submarines 5,712 5,175 5,264 Surface ships 1,872 1,607 1,648 Repair and other services 918 1,222 1,160 Total Marine Systems 8,502 8,004 8,072 Total revenue $ 36,193 $ 30,973 $ 30,561 Revenue by contract type was as follows: Year Ended December 31, 2018 Aerospace Combat Systems Information Technology Mission Systems Marine Systems Total Fixed-price $ 7,600 $ 5,406 $ 3,396 $ 2,711 $ 5,493 $ 24,606 Cost-reimbursement — 800 3,422 1,861 3,004 9,087 Time-and-materials 855 35 1,451 154 5 2,500 Total revenue $ 8,455 $ 6,241 $ 8,269 $ 4,726 $ 8,502 $ 36,193 Year Ended December 31, 2017 Fixed-price $ 7,479 $ 5,090 $ 1,465 $ 2,478 $ 4,808 $ 21,320 Cost-reimbursement — 823 2,305 1,838 3,186 8,152 Time-and-materials 650 36 640 165 10 1,501 Total revenue $ 8,129 $ 5,949 $ 4,410 $ 4,481 $ 8,004 $ 30,973 Year Ended December 31, 2016 Fixed-price $ 7,208 $ 4,629 $ 1,514 $ 2,737 $ 4,857 $ 20,945 Cost-reimbursement — 865 2,262 1,822 3,204 8,153 Time-and-materials 607 36 652 157 11 1,463 Total revenue $ 7,815 $ 5,530 $ 4,428 $ 4,716 $ 8,072 $ 30,561 Our segments operate under fixed-price, cost-reimbursement and time-and-materials contracts. Our production contracts are primarily fixed-price. Under these contracts, we agree to perform a specific scope of work for a fixed amount. Contracts for research, engineering, repair and maintenance, and other services are typically cost-reimbursement or time-and-materials. Under cost-reimbursement contracts, the customer reimburses contract costs incurred and pays a fixed, incentive or award-based fee. These fees are determined by our ability to achieve targets set in the contract, such as cost, quality, schedule and performance. Under time-and-materials contracts, the customer pays a fixed hourly rate for direct labor and generally reimburses us for the cost of materials. Each of these contract types presents advantages and disadvantages. Typically, we assume more risk with fixed-price contracts. However, these types of contracts offer additional profits when we complete the work for less than originally estimated. Cost-reimbursement contracts generally subject us to lower risk. Accordingly, the associated base fees are usually lower than fees earned on fixed-price contracts. Under time-and-materials contracts, our profit may vary if actual labor-hour rates vary significantly from the negotiated rates. Also, because these contracts can provide little or no fee for managing material costs, the content mix can impact profitability. Revenue by customer was as follows: Year Ended December 31, 2018 Aerospace Combat Systems Information Technology Mission Systems Marine Systems Total U.S. government: Department of Defense (DoD) $ 236 $ 2,903 $ 3,291 $ 3,224 $ 8,098 $ 17,752 Non-DoD — 8 4,712 506 2 5,228 Foreign Military Sales (FMS) 98 317 22 44 145 626 Total U.S. government 334 3,228 8,025 3,774 8,245 23,606 U.S. commercial 4,175 251 163 138 245 4,972 Non-U.S. government 551 2,698 81 662 10 4,002 Non-U.S. commercial 3,395 64 — 152 2 3,613 Total revenue $ 8,455 $ 6,241 $ 8,269 $ 4,726 $ 8,502 $ 36,193 Year Ended December 31, 2017 U.S. government: DoD $ 189 $ 2,702 $ 1,802 $ 3,027 $ 7,721 $ 15,441 Non-DoD — 8 2,340 556 — 2,904 FMS 42 374 22 46 192 676 Total U.S. government 231 3,084 4,164 3,629 7,913 19,021 U.S. commercial 3,885 220 214 108 71 4,498 Non-U.S. government 210 2,580 32 607 13 3,442 Non-U.S. commercial 3,803 65 — 137 7 4,012 Total revenue $ 8,129 $ 5,949 $ 4,410 $ 4,481 $ 8,004 $ 30,973 Year Ended December 31, 2016 U.S. government: DoD $ 231 $ 2,274 $ 1,781 $ 3,287 $ 7,507 $ 15,080 Non-DoD — 7 2,343 525 8 2,883 FMS 130 333 23 25 202 713 Total U.S. government 361 2,614 4,147 3,837 7,717 18,676 U.S. commercial 3,501 287 259 108 329 4,484 Non-U.S. government 496 2,520 8 613 26 3,663 Non-U.S. commercial 3,457 109 14 158 — 3,738 Total revenue $ 7,815 $ 5,530 $ 4,428 $ 4,716 $ 8,072 $ 30,561 Contract Balances. The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities) on the Consolidated Balance Sheet. In our defense segments, amounts are billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals (e.g., biweekly or monthly) or upon achievement of contractual milestones. Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. However, we sometimes receive advances or deposits from our customers, particularly on our international contracts, before revenue is recognized, resulting in contract liabilities. These assets and liabilities are reported on the Consolidated Balance Sheet on a contract-by-contract basis at the end of each reporting period. In our Aerospace segment, we generally receive deposits from customers upon contract execution and upon achievement of contractual milestones. These deposits are liquidated when revenue is recognized. Changes in the contract asset and liability balances during the year ended December 31, 2018 , were not materially impacted by any other factors except for the acquisition of CSRA in our Information Technology segment as further discussed in Note B and the delays in payment on an international wheeled armored vehicle contract in our Combat Systems segment as further discussed in Note H. Revenue recognized in 2018 , 2017 and 2016 that was included in the contract liability balance at the beginning of each year was $4.3 billion , $4.3 billion and $4.2 billion , respectively. This revenue represented primarily the sale of business-jet aircraft.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE We compute basic earnings per share (EPS) using net earnings for the period and the weighted average number of common shares outstanding during the period. Basic weighted average shares outstanding have decreased in 2018 and 2017 due to share repurchases. See Note M for further discussion of our share repurchases. Diluted EPS incorporates the additional shares issuable upon the assumed exercise of stock options and the release of restricted stock and restricted stock units (RSUs). Basic and diluted weighted average shares outstanding were as follows (in thousands): Year Ended December 31 2018 2017 2016 Basic weighted average shares outstanding 295,262 299,172 304,707 Dilutive effect of stock options and restricted stock/RSUs* 3,898 5,465 5,680 Diluted weighted average shares outstanding 299,160 304,637 310,387 * Excludes outstanding options to purchase shares of common stock that had exercise prices in excess of the average market price of our common stock during the year and, therefore, the effect of including these options would be antidilutive. These options totaled 3,143 in 2018 , 1,547 in 2017 and 4,201 in 2016 .

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between marketplace participants. Various valuation approaches can be used to determine fair value, each requiring different valuation inputs. The following hierarchy classifies the inputs used to determine fair value into three levels: • Level 1 - quoted prices in active markets for identical assets or liabilities; • Level 2 - inputs, other than quoted prices, observable by a marketplace participant either directly or indirectly; and • Level 3 - unobservable inputs significant to the fair value measurement. We did not have any significant non-financial assets or liabilities measured at fair value on December 31, 2018 or 2017 . Our financial instruments include cash and equivalents, accounts receivable and payable, marketable securities held in trust and other investments, short- and long-term debt, and derivative financial instruments. The carrying values of cash and equivalents and accounts receivable and payable on the Consolidated Balance Sheet approximate their fair value. The following tables present the fair values of our other financial assets and liabilities on December 31, 2018 and 2017 , and the basis for determining their fair values: Carrying Value Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets (Liabilities) December 31, 2018 Measured at fair value: Marketable securities held in trust: Cash and equivalents $ 29 $ 29 $ 23 $ 6 $ — Available-for-sale debt securities 121 121 — 121 — Equity securities 52 52 52 — — Other investments 4 4 — — 4 Cash flow hedges (69 ) (69 ) — (69 ) — Measured at amortized cost: Short- and long-term debt principal (12,518 ) (12,346 ) — (12,346 ) — December 31, 2017 Measured at fair value: Marketable securities held in trust: Cash and equivalents $ 20 $ 20 $ 15 $ 5 $ — Available-for-sale debt securities 117 117 — 117 — Equity securities 54 54 54 — — Other investments 4 4 — — 4 Cash flow hedges (105 ) (105 ) — (105 ) — Measured at amortized cost: Short- and long-term debt principal (4,032 ) (3,974 ) — (3,974 ) — Our Level 1 assets include investments in publicly traded equity securities valued using quoted prices from the market exchanges. The fair value of our Level 2 assets and liabilities is determined under a market approach using valuation models that incorporate observable inputs such as interest rates, bond yields and quoted prices for similar assets. Our Level 3 assets include direct private equity investments that are measured using inputs unobservable to a marketplace participant.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Income Tax Provision. We calculate our provision for federal, state and international income taxes based on current tax law. U.S. federal tax reform was enacted on December 22, 2017, and has several key provisions impacting the accounting for and reporting of income taxes. The most significant provision reduced the U.S. corporate statutory tax rate from 35% to 21% beginning on January 1, 2018. We recorded the effect of the change in tax law in the fourth quarter of 2017. The provision for income taxes and effective tax rate in 2017 included a $119 unfavorable impact from the change in tax law. The impact was due primarily to the remeasurement of our U.S. federal deferred tax assets and liabilities at the tax rate expected to apply when the temporary differences are realized/settled (remeasured at a rate of 21% versus 35% for the majority of our deferred tax assets and liabilities). The following is a summary of our net provision for income taxes for continuing operations: Year Ended December 31 2018 2017 2016 Current: U.S. federal $ 587 $ 656 $ 698 State 48 31 24 International 95 77 71 Total current 730 764 793 Deferred: U.S. federal (37 ) 215 140 State 8 7 7 International 26 60 37 Adjustment for enacted change in U.S. tax law — 119 — Total deferred (3 ) 401 184 Provision for income taxes, net $ 727 $ 1,165 $ 977 Net income tax payments $ 532 $ 617 $ 959 The reported tax provision differs from the amounts paid because some income and expense items are recognized in different time periods for financial reporting than for income tax purposes. State and local income taxes allocable to U.S. government contracts are included in operating costs and expenses in the Consolidated Statement of Earnings and, therefore, are not included in the provision above. The reconciliation from the statutory federal income tax rate to our effective income tax rate follows: Year Ended December 31 2018 2017 2016 Statutory federal income tax rate 21.0 % 35.0 % 35.0 % State tax on commercial operations, net of federal benefits 1.1 0.6 0.6 Impact of international operations 0.6 (4.5 ) (4.0 ) Domestic production deduction — (1.5 ) (1.5 ) Foreign derived intangible income (1.2 ) — — Equity-based compensation (1.1 ) (2.6 ) (2.3 ) Domestic tax credits (1.1 ) (0.8 ) (0.9 ) Contract close-outs (0.5 ) — — Adoption impact of enacted change in U.S. tax law — 2.9 — Other, net (1.0 ) (0.5 ) (0.2 ) Effective income tax rate 17.8 % 28.6 % 26.7 % Net Deferred Tax Liability. The tax effects of temporary differences between reported earnings and taxable income consisted of the following: December 31 2018 2017 Retirement benefits $ 1,055 $ 935 Tax loss and credit carryforwards 393 437 Salaries and wages 160 137 Workers’ compensation 138 139 Other 351 335 Deferred assets 2,097 1,983 Valuation allowances (336 ) (402 ) Net deferred assets $ 1,761 $ 1,581 Intangible assets $ (1,061 ) $ (688 ) Contract accounting methods (530 ) (500 ) Property, plant and equipment (265 ) (182 ) Capital Construction Fund qualified ships (160 ) (159 ) Other (284 ) (221 ) Deferred liabilities $ (2,300 ) $ (1,750 ) Net deferred tax liability $ (539 ) $ (169 ) Our deferred tax assets and liabilities are included in other noncurrent assets and liabilities on the Consolidated Balance Sheet. Our net deferred tax liability consisted of the following: December 31 2018 2017 Deferred tax asset $ 38 $ 75 Deferred tax liability (577 ) (244 ) Net deferred tax liability $ (539 ) $ (169 ) We believe it is more likely than not that we will generate sufficient taxable income in future periods to realize our deferred tax assets, subject to the valuation allowances recognized. Our deferred tax balance associated with our retirement benefits includes a deferred tax asset of $1 billion on December 31, 2018 and 2017 , related to the amounts recorded in accumulated other comprehensive loss (AOCL) to recognize the funded status of our retirement plans. See Notes M and Q for additional details. One of our deferred tax liabilities results from our participation in the Capital Construction Fund (CCF), a program established by the U.S. government and administered by the Maritime Administration that supports the acquisition, construction, reconstruction or operation of U.S. flag merchant marine vessels. The program allows us to defer federal and state income taxes on earnings derived from eligible programs as long as the proceeds are deposited in the fund and withdrawals are used for qualified activities. We had U.S. government accounts receivable pledged (and thereby deposited) to the CCF of $483 and $692 on December 31, 2018 and 2017 , respectively. On December 31, 2018 , we had net operating loss carryforwards of $1 billion that begin to expire in 2019 and tax credit carryforwards of $135 that begin to expire in 2019. Tax Uncertainties. For all periods open to examination by tax authorities, we periodically assess our liabilities and contingencies based on the latest available information. Where we believe there is more than a 50% chance that our tax position will not be sustained, we record our best estimate of the resulting tax liability, including interest, in the Consolidated Financial Statements. We include any interest or penalties incurred in connection with income taxes as part of income tax expense. The total amount of these tax liabilities on December 31, 2018 , was not material to our results of operations, financial condition or cash flows. We participate in the Internal Revenue Service (IRS) Compliance Assurance Process (CAP), a real-time audit of our consolidated federal corporate income tax return. The IRS has examined our consolidated federal income tax returns through 2017. We do not expect the resolution of tax matters for open years to have a material impact on our results of operations, financial condition, cash flows or effective tax rate. Based on all known facts and circumstances and current tax law, we believe the total amount of any unrecognized tax benefits on December 31, 2018 , was not material to our results of operations, financial condition or cash flows, and if recognized, would not have a material impact on our effective tax rate. In addition, there are no tax positions for which it is reasonably possible that the unrecognized tax benefits will vary significantly over the next 12 months, producing, individually or in the aggregate, a material effect on our results of operations, financial condition or cash flows.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2018
Accounts Receivable, Net [Abstract]
Accounts Receivable	ACCOUNTS RECEIVABLE Accounts receivable represent amounts billed and currently due from customers. Payment is typically received from our customers either at periodic intervals (e.g., biweekly or monthly) or upon achievement of contractual milestones. Accounts receivable consisted of the following: December 31 2018 2017 Non-U.S. government $ 2,035 $ 2,228 U.S. government 1,189 971 Commercial 535 418 Total accounts receivable $ 3,759 $ 3,617 Receivables from non-U.S. government customers included amounts related to long-term production programs for the Spanish Ministry of Defence of $1.9 billion and $2.1 billion on December 31, 2018 and 2017 , respectively. A different ministry, the Spanish Ministry of Industry, has funded work on these programs in advance of costs incurred by the company. The cash advances are reported on the Consolidated Balance Sheet in current customer advances and deposits and will be repaid to the Ministry of Industry as we collect on the outstanding receivables from the Ministry of Defence. The net amounts for these programs on December 31, 2018 and 2017 , were advance payments of $338 and $284 , respectively. With respect to our other receivables, we expect to collect substantially all of the year-end 2018 balance during 2019 .

Unbilled Receivables

Unbilled Receivables	12 Months Ended
	Dec. 31, 2018
Contractors [Abstract]
Unbilled Receivables	UNBILLED RECEIVABLES Unbilled receivables represent revenue recognized on long-term contracts (contract costs and estimated profits) less associated advances and progress billings. These amounts will be billed in accordance with the agreed-upon contractual terms. Unbilled receivables consisted of the following: December 31 2018 2017 Unbilled revenue $ 27,908 $ 21,845 Advances and progress billings (21,332 ) (16,605 ) Net unbilled receivables $ 6,576 $ 5,240 Excluding the acquisition of CSRA, the increase in net unbilled receivables in 2018 was primarily on an international wheeled armored vehicle contract in our Combat Systems segment. At December 31, 2018 , the net unbilled receivable related to this contract was $1.9 billion . Our contract is with the Canadian government, who is selling the vehicles to an international customer. We have experienced delays in payment under the contract. We continue to meet our obligations under the contract and are entitled to payment for work performed. Therefore, we expect to collect the full amount currently outstanding. G&A costs in unbilled revenue on December 31, 2018 and 2017 , were $381 and $282 , respectively. Contract costs also may include estimated contract recoveries for matters such as contract changes and claims for unanticipated contract costs. We record revenue associated with these matters only when the amount of recovery can be estimated reliably and realization is probable. We expect to bill substantially all of our year-end 2018 net unbilled receivables balance during 2019 . The amount not expected to be billed in 2019 results primarily from the agreed-upon contractual billing terms.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventories	INVENTORIES The majority of our inventories are for business-jet aircraft. Our inventories are stated at the lower of cost or net realizable value. Work in process represents largely labor, material and overhead costs associated with aircraft in the manufacturing process and is based primarily on the estimated average unit cost in a production lot. Raw materials are valued primarily on the first-in, first-out method. We record pre-owned aircraft acquired in connection with the sale of new aircraft at the lower of the trade-in value or the estimated net realizable value. Inventories consisted of the following: December 31 2018 2017 Work in process $ 4,357 $ 3,872 Raw materials 1,504 1,357 Finished goods 33 51 Pre-owned aircraft 83 23 Total inventories $ 5,977 $ 5,303 The increase in total inventories was due primarily to the ramp-up in production of the new G500 and G600 aircraft programs in our Aerospace segment. Customer deposits associated with these aircraft, which are reflected in customer advances and deposits and other noncurrent liabilities on the Consolidated Balance Sheet, have also increased. We received type certification from the U.S. Federal Aviation Administration (FAA) and delivered the first G500 aircraft in the third quarter of 2018. Additionally, we are anticipating FAA type certification and entry into service in 2019 of the new G600 aircraft.

Property, Plant And Equipment,

Property, Plant And Equipment, Net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant And Equipment, Net	PROPERTY, PLANT AND EQUIPMENT, NET Property, plant and equipment (PP&E) is carried at historical cost, net of accumulated depreciation. PP&E by major asset class consisted of the following: December 31 2018 2017 Machinery and equipment $ 5,534 $ 4,736 Buildings and improvements 3,011 2,837 Land and improvements 386 357 Construction in process 472 307 Total PP&E 9,403 8,237 Accumulated depreciation (5,055 ) (4,720 ) PP&E, net $ 4,348 $ 3,517 We depreciate most of our assets using the straight-line method and the remainder using accelerated methods. Buildings and improvements are depreciated over periods of up to 50 years . Machinery and equipment are depreciated over periods of up to 30 years . Our government customers provide certain facilities and equipment for our use that are not included above.

Debt

Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Debt	DEBT Debt consisted of the following: December 31 2018 2017 Fixed-rate notes due: Interest rate: May 2020 2.875% $ 2,000 $ — May 2021 3.000% 2,000 — July 2021 3.875% 500 500 November 2022 2.250% 1,000 1,000 May 2023 3.375% 750 — August 2023 1.875% 500 500 November 2024 2.375% 500 500 May 2025 3.500% 750 — August 2026 2.125% 500 500 November 2027 2.625% 500 500 May 2028 3.750% 1,000 — November 2042 3.600% 500 500 Floating-rate notes due: May 2020 3-month LIBOR + 0.29% 500 — May 2021 3-month LIBOR + 0.38% 500 — Commercial paper 2.568% 850 — Other Various 168 32 Total debt principal 12,518 4,032 Less unamortized debt issuance costs and discounts 101 50 Total debt 12,417 3,982 Less current portion 973 2 Long-term debt $ 11,444 $ 3,980 In April 2018, we borrowed $7.5 billion under a short-term credit facility to finance, in part, the acquisition of CSRA. In May 2018, we issued $7.5 billion of fixed- and floating-rate notes to repay the borrowings under this facility. We entered into interest rate swap contracts that exchange the floating interest rates on the $500 notes due in May 2020 and May 2021 for fixed rates. The result of the interest rate swap contracts is effective interest rates on the floating-rate notes that are the same as the rates on the fixed-rate notes due in May 2020 and May 2021 . See Note N for further discussion of our derivative financial instruments. Interest payments associated with our debt were $312 in 2018 , $93 in 2017 and $83 in 2016 . Our fixed- and floating-rate notes are fully and unconditionally guaranteed by several of our 100 %-owned subsidiaries. See Note S for condensed consolidating financial statements. We have the option to redeem the fixed-rate notes prior to their maturity in whole or in part for the principal plus any accrued but unpaid interest and applicable make-whole amounts. The aggregate amounts of scheduled principal maturities of our debt are as follows: Year Ended December 31 Debt Principal 2019 $ 973 2020 2,501 2021 3,002 2022 1,002 2023 1,252 Thereafter 3,788 Total debt principal $ 12,518 On December 31, 2018 , we had $850 of commercial paper outstanding with a dollar-weighted average interest rate of 2.568% . We have $5 billion in committed bank credit facilities for general corporate purposes and working capital needs and to support our commercial paper issuances. These credit facilities include a $2 billion 364 -day facility expiring in March 2019 , a $1 billion multi-year facility expiring in November 2020 and a $2 billion multi-year facility expiring in March 2023 . We may renew or replace these credit facilities in whole or in part at or prior to their expiration dates. Our credit facilities are guaranteed by several of our 100 %-owned subsidiaries. We also have an effective shelf registration on file with the Securities and Exchange Commission that allows us to access the debt markets. Our financing arrangements contain a number of customary covenants and restrictions. We were in compliance with all covenants and restrictions on December 31, 2018 .

Other Liabilities

Other Liabilities	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Other Liabilities	OTHER LIABILITIES A summary of significant other liabilities by balance sheet caption follows: December 31 2018 2017 Salaries and wages $ 952 $ 786 Retirement benefits 272 295 Workers’ compensation 244 320 Fair value of cash flow hedges 141 180 Other (a) 1,708 1,317 Total other current liabilities $ 3,317 $ 2,898 Retirement benefits $ 4,422 $ 4,408 Customer deposits on commercial contracts 726 814 Deferred income taxes 577 244 Other (b) 1,768 1,066 Total other liabilities $ 7,493 $ 6,532 (a) Consists primarily of dividends payable, taxes payable, capital lease obligations, environmental remediation reserves, warranty reserves, deferred revenue and supplier contributions in the Aerospace segment, liabilities of discontinued operations, and insurance-related costs. (b) Consists primarily of capital lease obligations, warranty reserves, workers’ compensation liabilities and liabilities of discontinued operations.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	SHAREHOLDERS’ EQUITY Authorized Stock. Our authorized capital stock consists of 500 million shares of $1 per share par value common stock and 50 million shares of $1 per share par value preferred stock. The preferred stock is issuable in series, with the rights, preferences and limitations of each series to be determined by our board of directors. Shares Issued and Outstanding. On December 31, 2018 , we had 481,880,634 shares of common stock issued and 288,698,149 shares of common stock outstanding, including unvested restricted stock of 686,921 shares. On December 31, 2017 , we had 481,880,634 shares of common stock issued and 296,895,608 shares of common stock outstanding. No shares of our preferred stock were outstanding on either date. The only changes in our shares outstanding during 2018 and 2017 resulted from shares repurchased in the open market and share activity under our equity compensation plans. See Note P for additional details. Share Repurchases. Our board of directors from time to time authorizes management’s repurchase of outstanding shares of our common stock on the open market. On December 5, 2018, the board of directors authorized management to repurchase up to 10 million additional shares of the company’s outstanding stock. In 2018 , we repurchased 10.1 million of our outstanding shares for $1.8 billion . On December 31, 2018 , 7.5 million shares remained authorized by our board of directors for repurchase, approximately 3% of our total shares outstanding. We repurchased 7.8 million shares for $1.5 billion in 2017 and 14.2 million shares for $2 billion in 2016 . Dividends per Share. Our board of directors declared dividends per share of $3.72 in 2018 , $3.36 in 2017 and $3.04 in 2016 . We paid cash dividends of $1.1 billion in 2018 , $986 in 2017 and $911 in 2016 . Accumulated Other Comprehensive Loss. The changes, pretax and net of tax, in each component of AOCL consisted of the following: Losses on Cash Flow Hedges Unrealized Gains on Marketable Securities Foreign Currency Translation Adjustments Changes in Retirement Plans’ Funded Status AOCL December 31, 2015 $ (487 ) $ 20 $ 181 $ (2,997 ) $ (3,283 ) Other comprehensive loss, pretax 191 (9 ) (112 ) (192 ) (122 ) Benefit from income tax, net (49 ) 3 — 64 18 Other comprehensive loss, net of tax 142 (6 ) (112 ) (128 ) (104 ) December 31, 2016 (345 ) 14 69 (3,125 ) (3,387 ) Other comprehensive income, pretax 341 9 348 20 718 Provision for income tax, net (90 ) (4 ) (15 ) (42 ) (151 ) Other comprehensive income, net of tax 251 5 333 (22 ) 567 December 31, 2017 (94 ) 19 402 (3,147 ) (2,820 ) Cumulative effect adjustments (see Note A) (4 ) (19 ) — (615 ) (638 ) Other comprehensive loss, pretax 36 — (300 ) (61 ) (325 ) Benefit from income tax, net (9 ) — — 14 5 Other comprehensive loss, net of tax 27 — (300 ) (47 ) (320 ) December 31, 2018 $ (71 ) $ — $ 102 $ (3,809 ) $ (3,778 ) Current-period amounts reclassified out of AOCL related primarily to changes in our retirement plans’ funded status and consisted of pretax recognized net actuarial losses of $355 in 2018 , $358 in 2017 and $340 in 2016 . This was offset partially by pretax amortization of prior service credit of $50 in 2018 , $69 in 2017 and $74 in 2016 . These AOCL components are included in our net periodic pension and other post-retirement benefit cost. See Note Q for additional details.

Derivative Financial Instrument

Derivative Financial Instruments And Hedging Activities	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments And Hedging Activities	DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES We are exposed to market risk, primarily from foreign currency exchange rates, interest rates, commodity prices and investments. We may use derivative financial instruments to hedge some of these risks as described below. We do not use derivative financial instruments for trading or speculative purposes. Foreign Currency Risk. Our foreign currency exchange rate risk relates to receipts from customers, payments to suppliers and inter-company transactions denominated in foreign currencies. To the extent possible, we include terms in our contracts that are designed to protect us from this risk. Otherwise, we enter into derivative financial instruments, principally foreign currency forward purchase and sale contracts, designed to offset and minimize our risk. The dollar-weighted two -year average maturity of these instruments generally matches the duration of the activities that are at risk. Interest Rate Risk. Our financial instruments subject to interest rate risk include variable-rate commercial paper and fixed- and floating-rate long-term debt obligations. As described in Note K, we entered into derivative financial instruments, specifically interest rate swap contracts, to eliminate our floating-rate interest rate risk . The interest rate risk associated with our financial instruments is not material. Commodity Price Risk. We are subject to rising labor and commodity price risk, primarily on long-term, fixed-price contracts. To the extent possible, we include terms in our contracts that are designed to protect us from these risks. Some of the protective terms included in our contracts are considered derivative financial instruments but are not accounted for separately, because they are clearly and closely related to the host contract. We have not entered into any material commodity hedging contracts but may do so as circumstances warrant. We do not believe that changes in labor or commodity prices will have a material impact on our results of operations or cash flows. Investment Risk. Our investment policy allows for purchases of fixed-income securities with an investment-grade rating and a maximum maturity of up to five years. On December 31, 2018 , we held $963 in cash and equivalents, but held no marketable securities other than those held in trust to meet some of our obligations under workers’ compensation and non-qualified supplemental executive retirement plans . On December 31, 2018 , these marketable securities totaled $202 and were reflected at fair value on the Consolidated Balance Sheet in other current and noncurrent assets . See Note E for additional details. Hedging Activities. We had notional forward exchange and interest rate swap contracts outstanding of $5.8 billion and $4.3 billion on December 31, 2018 and 2017 , respectively. These derivative financial instruments are cash flow hedges, and are reflected at fair value on the Consolidated Balance Sheet in other current assets and liabilities. See Note E for additional details. Changes in fair value (gains and losses) related to derivative financial instruments that qualify as cash flow hedges are deferred in AOCL until the underlying transaction is reflected in earnings. Gains and losses on derivative financial instruments that do not qualify for hedge accounting are recorded each period in the Consolidated Statement of Earnings in operating costs and expenses or interest expense. The gains and losses on derivative financial instruments that do not qualify for hedge accounting generally offset losses and gains on the assets and liabilities being hedged. Gains and losses resulting from hedge ineffectiveness are recognized in the Consolidated Statement of Earnings for all derivative financial instruments, regardless of designation. Net gains and losses on derivative financial instruments recognized in earnings, including gains and losses related to hedge ineffectiveness, were not material to our results of operations in any of the past three years. Net gains and losses reclassified to earnings from AOCL were not material to our results of operations in any of the past three years, and we do not expect the amount of these gains and losses that will be reclassified to earnings in 2019 to be material. We had no material derivative financial instruments designated as fair value or net investment hedges on December 31, 2018 or 2017 . Foreign Currency Financial Statement Translation. We translate foreign currency balance sheets from our international businesses’ functional currency (generally the respective local currency) to U.S. dollars at the end-of-period exchange rates, and statements of earnings at the average exchange rates for each period. The resulting foreign currency translation adjustments are a component of AOCL. We do not hedge the fluctuation in reported revenue and earnings resulting from the translation of these international operations’ results into U.S. dollars. The impact of translating our non-U.S. operations’ revenue into U.S. dollars was not material to our results of operations in any of the past three years. In addition, the effect of changes in foreign exchange rates on non-U.S. cash balances was not material in any of the past three years.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	COMMITMENTS AND CONTINGENCIES Litigation In 2015, Electric Boat Corporation, a subsidiary of General Dynamics Corporation, received a Civil Investigative Demand from the U.S. Department of Justice regarding an investigation of potential False Claims Act violations relating to alleged failures of Electric Boat’s quality system with respect to allegedly non-conforming parts purchased from a supplier. In 2016, Electric Boat was made aware that it is a defendant in a lawsuit related to this matter filed under seal in U.S. district court. Also in 2016, the Suspending and Debarring Official for the U.S. Department of the Navy issued a Show Cause Letter to Electric Boat requesting that Electric Boat respond to the official’s concerns regarding Electric Boat’s oversight and management with respect to its quality assurance systems for subcontractors and suppliers. Electric Boat responded to the Show Cause Letter and has been engaged in discussions with the U.S. government. Given the current status of these matters, we are unable to express a view regarding the ultimate outcome or, if the outcome is adverse, to estimate an amount or range of reasonably possible loss. Depending on the outcome of these matters, there could be a material impact on our results of operations, financial condition and cash flows. Additionally, various other claims and legal proceedings incidental to the normal course of business are pending or threatened against us. These other matters relate to such issues as government investigations and claims, the protection of the environment , asbestos-related claims and employee-related matters. The nature of litigation is such that we cannot predict the outcome of these other matters. However, based on information currently available, we believe any potential liabilities in these other proceedings, individually or in the aggregate, will not have a material impact on our results of operations, financial condition or cash flows. Environmental We are subject to and affected by a variety of federal, state, local and foreign environmental laws and regulations. We are directly or indirectly involved in environmental investigations or remediation at some of our current and former facilities and third-party sites that we do not own but where we have been designated a Potentially Responsible Party (PRP) by the U.S. Environmental Protection Agency or a state environmental agency. Based on historical experience, we expect that a significant percentage of the total remediation and compliance costs associated with these facilities will continue to be allowable contract costs and, therefore, recoverable under U.S. government contracts. As required, we provide financial assurance for certain sites undergoing or subject to investigation or remediation. We accrue environmental costs when it is probable that a liability has been incurred and the amount can be reasonably estimated. Where applicable, we seek insurance recovery for costs related to environmental liabilities. We do not record insurance recoveries before collection is considered probable. Based on all known facts and analyses, we do not believe that our liability at any individual site, or in the aggregate, arising from such environmental conditions will be material to our results of operations, financial condition or cash flows. We also do not believe that the range of reasonably possible additional loss beyond what has been recorded would be material to our results of operations, financial condition or cash flows. Minimum Lease Payments Total expense under operating leases was $380 in 2018 , $309 in 2017 and $307 in 2016 . Operating leases are primarily for facilities and equipment. Future minimum lease payments are as follows: Year Ended December 31 Future Minimum Lease Payments 2019 $ 297 2020 234 2021 196 2022 154 2023 110 Thereafter 698 Total future minimum lease payments $ 1,689 Other Government Contracts. As a government contractor, we are subject to U.S. government audits and investigations relating to our operations, including claims for fines, penalties, and compensatory and treble damages. We believe the outcome of such ongoing government audits and investigations will not have a material impact on our results of operations, financial condition or cash flows. In the performance of our contracts, we routinely request contract modifications that require additional funding from the customer. Most often, these requests are due to customer-directed changes in the scope of work. While we are entitled to recovery of these costs under our contracts, the administrative process with our customer may be protracted. Based on the circumstances, we periodically file requests for equitable adjustment (REAs) that are sometimes converted into claims. In some cases, these requests are disputed by our customer. We believe our outstanding modifications, REAs and other claims will be resolved without material impact to our results of operations, financial condition or cash flows. Letters of Credit and Guarantees. In the ordinary course of business, we have entered into letters of credit, bank guarantees, surety bonds and other similar arrangements with financial institutions and insurance carriers totaling approximately $1.7 billion on December 31, 2018 . In addition, from time to time and in the ordinary course of business, we contractually guarantee the payment or performance of our subsidiaries arising under certain contracts. Aircraft Trade-ins. In connection with orders for new aircraft in contract backlog, our Aerospace segment has outstanding options with some customers to trade in aircraft as partial consideration in their new-aircraft transaction. These trade-in commitments are generally structured to establish the fair market value of the trade-in aircraft at a date generally 45 or fewer days preceding delivery of the new aircraft to the customer. At that time, the customer is required to either exercise the option or allow its expiration. Additionally, certain trade-in commitments are structured to guarantee a pre-determined trade-in value. In either case, any excess of the pre-established trade-in price above the fair market value at the time the new aircraft is delivered is treated as a reduction of revenue in the new-aircraft sales transaction. Labor Agreements. On December 31, 2018 , approximately one-fifth of the employees of our subsidiaries were working under collectively bargained terms and conditions, including 94 collective agreements that we have negotiated directly with unions and works councils. A number of these agreements expire within any given year. Historically, we have been successful at renegotiating these labor agreements without any material disruption of operating activities. In 2019 , we expect to negotiate the terms of 21 agreements covering approximately 5,500 employees. We do not expect the renegotiations will, either individually or in the aggregate, have a material impact on our results of operations, financial condition or cash flows. Product Warranties. We provide warranties to our customers associated with certain product sales. We record estimated warranty costs in the period in which the related products are delivered. The warranty liability recorded at each balance sheet date is based generally on the number of months of warranty coverage remaining for the products delivered and the average historical monthly warranty payments. Warranty obligations incurred in connection with long-term production contracts are accounted for within the contract estimates at completion. Our other warranty obligations, primarily for business-jet aircraft, are included in other current and noncurrent liabilities on the Consolidated Balance Sheet. The changes in the carrying amount of warranty liabilities for each of the past three years were as follows: Year Ended December 31 2018 2017 2016 Beginning balance $ 467 $ 474 $ 434 Warranty expense 129 146 155 Payments (102 ) (123 ) (100 ) Adjustments (14 ) (30 ) (15 ) Ending balance $ 480 $ 467 $ 474 Capital Leases. Capital lease liabilities represent obligations due under capital leases for the use of buildings and improvements, and machinery and equipment. The gross amount of assets recorded under capital leases was $485 and $19 with accumulated amortization of $61 and $3 as of December 31, 2018 and 2017, respectively. Amortization of capital lease assets is included within depreciation expense. The increase in capital lease liabilities in 2018 was due primarily to the acquisition of CSRA. The future minimum lease payments are as follows: Year Ended December 31 Future Minimum Lease Payments 2019 $ 92 2020 84 2021 78 2022 79 2023 30 Thereafter 70 Total future minimum lease payments 433 Less amount representing interest 95 Less amount representing executory costs 19 Present value of net minimum lease payments 319 Less current maturities of capital lease liability 64 Non-current capital lease liability $ 255

Equity Compensation Plans

Equity Compensation Plans	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Compensation Plans	EQUITY COMPENSATION PLANS Equity Compensation Overview. We have equity compensation plans for employees, as well as for non-employee members of our board of directors. The equity compensation plans seek to provide an effective means of attracting and retaining directors, officers and key employees, and to provide them with incentives to enhance our growth and profitability. Under the equity compensation plans, awards may be granted to officers, employees or non-employee directors in common stock, options to purchase common stock, restricted shares of common stock, participation units or any combination of these. Annually, we grant awards of stock options, restricted stock and RSUs to participants in our equity compensation plans in early March. Additionally, we may make limited ad hoc grants on a quarterly basis for new hires or promotions. We issue common stock under our equity compensation plans from treasury stock. On December 31, 2018 , in addition to the shares reserved for issuance upon the exercise of outstanding stock options, approximately 28 million shares have been authorized for awards that may be granted in the future. Equity-based Compensation Expense. Equity-based compensation expense is included in G&A expenses. The following table details the components of equity-based compensation expense recognized in net earnings in each of the past three years: Year Ended December 31 2018 2017 2016 Stock options $ 45 $ 34 $ 25 Restricted stock/RSUs 65 46 36 Total equity-based compensation expense, net of tax $ 110 $ 80 $ 61 Stock Options. Stock options granted under our equity compensation plans are issued with an exercise price at the fair value of our common stock determined by the average of the high and low stock prices as listed on the New York Stock Exchange on the date of grant. The majority of our outstanding stock options vest over three years, with 50% of the options vesting after two years and the remaining 50% vesting the following year, and expire 10 years after the grant date. We recognize compensation expense related to stock options on a straight-line basis over the vesting period of the awards, net of estimated forfeitures. Estimated forfeitures are based on our historical forfeiture experience. We estimate the fair value of stock options on the date of grant using the Black-Scholes option pricing model with the following assumptions for each of the past three years: Year Ended December 31 2018 2017 2016 Expected volatility 17.6-18.2% 17.3-19.4% 19.1-20.0% Weighted average expected volatility 17.6% 19.4% 20.0% Expected term (in months) 68 68 70 Risk-free interest rate 2.6-2.9% 2.0-2.2% 1.5-1.6% Expected dividend yield 1.8% 1.8% 2.0% We determine the above assumptions based on the following: • Expected volatility is based on the historical volatility of our common stock over a period equal to the expected term of the option. • Expected term is based on assumptions used by a set of comparable peer companies. • Risk-free interest rate is the yield on a U.S. Treasury zero-coupon issue with a remaining term equal to the expected term of the option at the grant date. • Expected dividend yield is based on our historical dividend yield. The resulting weighted average fair value per stock option granted (in dollars) was $37.42 in 2018 , $33.09 in 2017 and $22.11 in 2016 . Stock option expense reduced pretax operating earnings (and on a diluted per-share basis) by $57 ( $0.15 ) in 2018 , $53 ( $0.11 ) in 2017 and $39 ( $0.08 ) in 2016 . Compensation expense for stock options is reported as a Corporate expense for segment reporting purposes (see Note R). On December 31, 2018 , we had $73 of unrecognized compensation cost related to stock options, which is expected to be recognized over a weighted average period of 1.9 years . A summary of stock option activity during 2018 follows: In Shares and Dollars Shares Under Option Weighted Average Exercise Price Per Share Outstanding on December 31, 2017 10,620,389 $ 126.08 Granted 1,730,430 223.06 Exercised (1,388,110 ) 104.48 Forfeited/canceled (197,514 ) 182.08 Outstanding on December 31, 2018 10,765,195 $ 143.43 Vested and expected to vest on December 31, 2018 10,595,953 $ 142.32 Exercisable on December 31, 2018 6,119,560 $ 109.19 Summary information with respect to our stock options’ intrinsic value and remaining contractual term on December 31, 2018 , follows: Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding 5.5 $ 320 Vested and expected to vest 5.4 319 Exercisable 3.4 294 In the table above, intrinsic value is calculated as the excess, if any, of the market price of our stock on the last trading day of the year over the exercise price of the options. For stock options exercised, intrinsic value is calculated as the difference between the market price on the date of exercise and the exercise price. The total intrinsic value of stock options exercised was $147 in 2018 , $215 in 2017 and $263 in 2016 . Restricted Stock/RSUs. The fair value of restricted stock and RSUs equals the average of the high and low market prices of our common stock as listed on the New York Stock Exchange on the date of grant. Grants of restricted stock are awards of shares of common stock. Participation units represent obligations that have a value derived from or related to the value of our common stock. These include stock appreciation rights, phantom stock units and RSUs, and are payable in cash or common stock. Restricted stock and RSUs generally vest over a three -year restriction period after the grant date, during which recipients may not sell, transfer, pledge, assign or otherwise convey their restricted shares to another party. During this period, restricted stock recipients receive cash dividends on their restricted shares and are entitled to vote those shares, while RSU recipients receive dividend-equivalent units instead of cash dividends and are not entitled to vote their RSUs or dividend-equivalent units. We grant RSUs with a performance measure derived from a non-GAAP-based management metric, return on invested capital (ROIC). Depending on the company’s performance with respect to this metric, the number of RSUs earned may be less than, equal to or greater than the original number of RSUs awarded subject to a payout range. We generally recognize compensation expense related to restricted stock and RSUs on a straight-line basis over the vesting period of the awards. Compensation expense related to restricted stock and RSUs reduced pretax operating earnings (and on a diluted per-share basis) by $83 ( $0.22 ) in 2018 , $70 ( $0.15 ) in 2017 and $56 ( $0.12 ) in 2016 . Compensation expense for restricted stock and RSUs is reported as an operating expense for segment reporting purposes (see Note R). On December 31, 2018 , we had $53 of unrecognized compensation cost related to restricted stock and RSUs, which is expected to be recognized over a weighted average period of 1.6 years . A summary of restricted stock and RSU activity during 2018 follows: In Shares and Dollars Shares/ Share-Equivalent Units Weighted Average Grant-Date Fair Value Per Share Nonvested at December 31, 2017 1,983,173 $ 135.38 Granted 482,700 204.97 Vested (1,163,702 ) 122.59 Forfeited (39,895 ) 195.99 Nonvested at December 31, 2018 1,262,276 $ 171.62 The total fair value of vesting shares was $242 in 2018 , $200 in 2017 and $68 in 2016 .

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Retirement Plans	RETIREMENT PLANS We provide defined-contribution benefits to eligible employees, as well as some remaining defined-benefit pension and other post-retirement benefits. Substantially all of our plans use a December 31 measurement date consistent with our fiscal year. The following discussion reflects the inclusion of legacy CSRA plans assumed in connection with the acquisition as of the acquisition date. Retirement Plan Summary Information Defined-contribution Benefits. We provide eligible employees the opportunity to participate in defined-contribution savings plans (commonly known as 401(k) plans), which permit contributions on a before-tax and after-tax basis. Employees may contribute to various investment alternatives. In most of these plans, we match a portion of the employees’ contributions. Our contributions to these plans totaled $302 in 2018 , $274 in 2017 and $261 in 2016 . The defined-contribution plans held approximately 21 million shares of our common stock, representing approximately 7% of our outstanding shares on December 31, 2018 and 2017 . Pension Benefits. We have ten noncontributory and five contributory trusteed, qualified defined-benefit pension plans covering eligible government business employees, and two noncontributory and four contributory plans covering eligible commercial business employees, including some employees of our international operations. The primary factors affecting the benefits earned by participants in our pension plans are employees’ years of service and compensation levels. Our primary government pension plans, which comprise the majority of our unfunded obligation, were closed to new salaried participants on January 1, 2007. Additionally, we made changes to these plans for certain participants effective in 2014 that limit or cease the benefits that accrue for future service. We made similar changes to our primary commercial pension plan in 2015. We also sponsor one funded and several unfunded non-qualified supplemental executive retirement plans, which provide participants with additional benefits, including excess benefits over limits imposed on qualified plans by federal tax law. Other Post-retirement Benefits. We maintain plans that provide post-retirement healthcare and life insurance coverage for certain employees and retirees. These benefits vary by employment status, age, service and salary level at retirement. The coverage provided and the extent to which the retirees share in the cost of the program vary throughout the company. The plans provide health and life insurance benefits only to those employees who retire directly from our service and not to those who terminate service prior to eligibility for retirement. Contributions and Benefit Payments It is our policy to fund our defined-benefit retirement plans in a manner that optimizes the tax deductibility and contract recovery of contributions considered within our capital deployment framework. Therefore, we may make discretionary contributions in addition to the required contributions determined in accordance with IRS regulations. In 2018, in addition to our required contributions of approximately $315 , we made a discretionary contribution of $255 , resulting in total pension plan contributions of approximately $570 in 2018 . The additional contribution was considered to be a significant event in accordance with ASC Topic 715 and, therefore, triggered a remeasurement of the 2018 net periodic defined-benefit pension cost. In 2019 , our required contributions are approximately $190 . We maintain several tax-advantaged accounts, primarily Voluntary Employees’ Beneficiary Association (VEBA) trusts, to fund the obligations for some of our other post-retirement benefit plans. For non-funded plans, claims are paid as received. Contributions to our other post-retirement benefit plans were not material in 2018 and are not expected to be material in 2019 . We expect the following benefits to be paid from our retirement plans over the next 10 years: Pension Benefits Other Post-retirement 2019 $ 816 $ 68 2020 846 67 2021 873 66 2022 899 65 2023 927 64 2024-2028 4,947 296 Government Contract Considerations Our contractual arrangements with the U.S. government provide for the recovery of contributions to our pension and other post-retirement benefit plans covering employees working in our defense segments. For non-funded plans, our government contracts allow us to recover claims paid. Following payment, these recoverable amounts are allocated to contracts and billed to the customer in accordance with the Cost Accounting Standards (CAS) and specific contractual terms. For some of these plans, the cumulative pension and other post-retirement benefit cost exceeds the amount currently allocable to contracts. To the extent we consider recovery of the cost to be probable based on our backlog and probable follow-on contracts, we defer the excess in other contract costs in other current assets on the Consolidated Balance Sheet until the cost is allocable to contracts. See Note A for a discussion of our other contract costs. For other plans, the amount allocated to contracts and included in revenue has exceeded the plans’ cumulative benefit cost. We have similarly deferred recognition of these excess earnings on the Consolidated Balance Sheet. Defined-benefit Retirement Plan Summary Financial Information Estimating retirement plan assets, liabilities and costs requires the extensive use of actuarial assumptions. These include the long-term rate of return on plan assets, the interest rates used to discount projected benefit payments, healthcare cost trend rates and future salary increases. Given the long-term nature of the assumptions being made, actual outcomes can and often do differ from these estimates. Our annual benefit cost consists of three primary elements: the cost of benefits earned by employees for services rendered during the year, an interest charge on our plan liabilities and an assumed return on our plan assets for the year. The annual cost also includes gains and losses resulting from changes in actuarial assumptions, differences between the actual and assumed long-term rate of return on assets, and gains and losses resulting from changes we make to plan benefit terms. We recognize an asset or liability on the Consolidated Balance Sheet equal to the funded status of each of our defined-benefit retirement plans. The funded status is the difference between the fair value of the plan’s assets and its benefit obligation. Changes in plan assets and liabilities due to differences between actuarial assumptions and the actual results of the plan are deferred in AOCL rather than charged to earnings. These differences are then amortized over future years as a component of our annual benefit cost. We amortize actuarial differences under qualified plans on a straight-line basis over the average remaining service period of eligible employees. If all of a plan’s participants are inactive or are not accruing additional benefits, we amortize these differences over the average remaining life expectancy of the plan participants. We recognize the difference between the actual and expected return on plan assets for qualified plans over five years. The deferral of these differences reduces the volatility of our annual benefit cost that can result either from year-to-year changes in the assumptions or from actual results that are not necessarily representative of the long-term financial position of these plans. We recognize differences under nonqualified plans immediately. Net annual defined-benefit pension and other post-retirement benefit cost (credit) consisted of the following: Pension Benefits Year Ended December 31 2018 2017 2016 Service cost $ 180 $ 168 $ 173 Interest cost 532 453 456 Expected return on plan assets (856 ) (679 ) (713 ) Recognized net actuarial loss 359 362 343 Amortization of prior service credit (46 ) (66 ) (68 ) Net annual benefit cost $ 169 $ 238 $ 191 Other Post-retirement Benefits Year Ended December 31 2018 2017 2016 Service cost $ 10 $ 9 $ 10 Interest cost 33 30 34 Expected return on plan assets (40 ) (34 ) (33 ) Recognized net actuarial gain (4 ) (4 ) (3 ) Amortization of prior service credit (4 ) (3 ) (6 ) Net annual benefit (credit) cost $ (5 ) $ (2 ) $ 2 As discussed in Note A, the service cost component of net annual benefit cost (credit) is reported separately from the other components of net annual benefit cost (credit) in accordance with ASU 2017-07. The following is a reconciliation of the benefit obligations and plan/trust assets, and the resulting funded status, of our defined-benefit retirement plans: Pension Benefits Other Post-retirement Benefits Year Ended December 31 2018 2017 2018 2017 Change in Benefit Obligation Benefit obligation at beginning of year $ (14,212 ) $ (13,022 ) $ (996 ) $ (1,005 ) Service cost (180 ) (168 ) (10 ) (9 ) Interest cost (532 ) (453 ) (33 ) (30 ) Acquisitions (2,758 ) — (62 ) — Amendments 15 1 — — Actuarial gain (loss) 1,183 (1,098 ) 78 (42 ) Settlement/curtailment/other 23 (58 ) 21 27 Benefits paid 741 586 67 63 Benefit obligation at end of year $ (15,720 ) $ (14,212 ) $ (935 ) $ (996 ) Change in Plan/Trust Assets Fair value of assets at beginning of year $ 10,130 $ 8,980 $ 541 $ 499 Actual return on plan assets (749 ) 1,469 (4 ) 82 Acquisitions 2,328 — 77 — Employer contributions 571 199 1 3 Settlement/curtailment/other (26 ) 56 — — Benefits paid (722 ) (574 ) (45 ) (43 ) Fair value of assets at end of year $ 11,532 $ 10,130 $ 570 $ 541 Funded status at end of year $ (4,188 ) $ (4,082 ) $ (365 ) $ (455 ) Amounts recognized on the Consolidated Balance Sheet consisted of the following: Pension Benefits Other Post-retirement Benefits December 31 2018 2017 2018 2017 Noncurrent assets $ 67 $ 133 $ 74 $ 33 Current liabilities (131 ) (145 ) (141 ) (150 ) Noncurrent liabilities (4,124 ) (4,070 ) (298 ) (338 ) Net liability recognized $ (4,188 ) $ (4,082 ) $ (365 ) $ (455 ) Amounts deferred in AOCL consisted of the following: Pension Benefits Other Post-retirement Benefits December 31 2018 2017 2018 2017 Net actuarial loss (gain) $ 4,959 $ 4,899 $ (37 ) $ (5 ) Prior service (credit) cost (95 ) (124 ) 1 (3 ) Total amount recognized in AOCL, pretax $ 4,864 $ 4,775 $ (36 ) $ (8 ) The following is a reconciliation of the change in AOCL for our defined-benefit retirement plans: Pension Benefits Other Post-retirement Benefits Year Ended December 31 2018 2017 2018 2017 Net actuarial loss (gain) $ 422 $ 308 $ (34 ) $ (6 ) Prior service cost (15 ) (1 ) — — Amortization of: Net actuarial (loss) gain from prior years (359 ) (362 ) 4 4 Prior service credit 46 66 4 3 Other* (5 ) 7 (2 ) (39 ) Change in AOCL, pretax $ 89 $ 18 $ (28 ) $ (38 ) * Includes foreign exchange translation, curtailment and other adjustments. The following table represents amounts deferred in AOCL on the Consolidated Balance Sheet on December 31, 2018 , that we expect to recognize in our retirement benefit cost in 2019 : Pension Other Post-retirement Net actuarial loss (gain) $ 280 $ (8 ) Prior service credit (18 ) (4 ) A pension plan’s funded status is the difference between the plan’s assets and its projected benefit obligation (PBO). The PBO is the present value of future benefits attributed to employee services rendered to date, including assumptions about future compensation levels. A pension plan’s accumulated benefit obligation (ABO) is the present value of future benefits attributed to employee services rendered to date, excluding assumptions about future compensation levels. The ABO for all defined-benefit pension plans was $15.5 billion and $13.9 billion on December 31, 2018 and 2017 , respectively. On December 31, 2018 and 2017 , some of our pension plans had an ABO that exceeded the plans’ assets. Summary information for those plans follows: December 31 2018 2017 PBO $ (15,067 ) $ (13,660 ) ABO (14,856 ) (13,398 ) Fair value of plan assets 10,832 9,526 Retirement Plan Assumptions We calculate the plan assets and liabilities for a given year and the net annual benefit cost for the subsequent year using assumptions determined as of December 31 of the year in question. The following table summarizes the weighted average assumptions used to determine our benefit obligations: Assumptions on December 31 2018 2017 Pension Benefits Benefit obligation discount rate 4.28 % 3.62 % Rate of increase in compensation levels 2.79 % 2.82 % Other Post-retirement Benefits Benefit obligation discount rate 4.24 % 3.64 % Healthcare cost trend rate: Trend rate for next year 6.50 % 6.50 % Ultimate trend rate 5.00 % 5.00 % Year rate reaches ultimate trend rate 2024 2024 The following table summarizes the weighted average assumptions used to determine our net annual benefit cost: Assumptions for Year Ended December 31 2018 2017 2016 Pension Benefits Discount rates: Benefit obligation 3.69 % 4.19 % 4.46 % Service cost 3.51 % 4.13 % 4.42 % Interest cost 3.34 % 3.56 % 3.71 % Expected long-term rate of return on assets 7.45 % 7.43 % 8.14 % Rate of increase in compensation levels 2.79 % 2.90 % 3.39 % Other Post-retirement Benefits Discount rates: Benefit obligation 3.64 % 4.11 % 4.35 % Service cost 3.79 % 4.34 % 4.52 % Interest cost 3.27 % 3.43 % 3.53 % Expected long-term rate of return on assets 7.75 % 7.76 % 7.81 % We base the discount rates on a current yield curve developed from a portfolio of high-quality, fixed-income investments with maturities consistent with the projected benefit payout period. We use the spot rate approach to identify individual spot rates along the yield curve that correspond with the timing of each projected service cost and discounted benefit obligation payment. We determine the long-term rates of return on assets based on consideration of historical and forward-looking returns and the current and expected asset allocation strategy. In 2017, we decreased the expected long-term rate of return on assets in our primary U.S. government and commercial pension plans by 75 basis points following an assessment of the historical and expected long-term returns of our various asset classes. Beginning in 2019, we will decrease the expected long-term rates of return on assets in our primary U.S. other post-retirement benefit plans by 100 basis points, following an assessment of the historical and expected long-term returns of our various asset classes. This decrease is not expected to have a material impact on our 2019 benefit costs. Retirement plan assumptions are based on our best judgment, including consideration of current and future market conditions. Changes in these estimates impact future pension and other post-retirement benefit cost. As discussed above, we defer recognition of the cumulative benefit cost for our government plans in excess of costs allocated to contracts and included in revenue. Therefore, the impact of annual changes in financial reporting assumptions on the cost for these plans does not immediately affect our operating results. For our U.S. pension plans that represent the majority of our total obligation, the following hypothetical changes in the discount rates and expected long-term rates of return on plan assets would have had the following impact in 2018 : Increase 25 Basis Points Decrease 25 Basis Points Increase (decrease) to net pension cost from: Change in discount rates $ (24 ) $ 25 Change in long-term rates of return on plan assets (27 ) 27 A 25-basis-point change in these assumed rates would not have had a measurable impact on the benefit cost for our other post-retirement benefit plans in 2018 . For our healthcare plans, the effect of a 1% increase or decrease in the assumed healthcare cost trend rate on the 2018 net annual benefit cost is $4 and ($3) , respectively, and the effect on the December 31, 2018 , accumulated other post-retirement benefit obligation is $65 and ($52) , respectively. Plan Assets A committee of our board of directors is responsible for the strategic oversight of our defined-benefit retirement plan assets held in trust. Management develops investment policies and provides oversight of a third-party investment manager who reports to the committee on a regular basis. The outsourced third-party investment manager develops investment strategies and makes all day-to-day investment decisions related to defined-benefit retirement plan assets in accordance with our investment policy and target allocation percentages. Our investment policy endeavors to strike the appropriate balance among capital preservation, asset growth and current income. The objective of our investment policy is to generate future returns consistent with our assumed long-term rates of return used to determine our benefit obligations and net annual benefit cost. Target allocation percentages vary over time depending on the perceived risk and return potential of various asset classes and market conditions. At the end of 2018 , our asset allocation policy ranges were: Equities 48-68% Fixed income 20-48% Cash 0-5% Other asset classes 0-16% Approximately 75% of our pension plan assets are held in a single trust for our primary U.S. government and commercial pension plans. On December 31, 2018 , the trust was invested largely in publicly traded equities, fixed-income securities and commingled funds comprised of equity securities. The trust also invests in other asset classes consistent with our investment policy. Our investments in equity assets include U.S. and international securities and equity funds. Our investments in fixed-income assets include U.S. Treasury and U.S. agency securities, corporate bonds, mortgage-backed securities and other asset-backed securities. Our investment policy allows the use of derivative instruments when appropriate to reduce anticipated asset volatility, to gain exposure to an asset class or to adjust the duration of fixed-income assets. Assets for our non-U.S. pension plans are held in trusts in the countries in which the related operations reside. Our non-U.S. operations maintain investment policies for their individual plans based on country-specific regulations. The non-U.S. plan assets are invested primarily in commingled funds comprised of equity and fixed-income securities. We hold assets in VEBA trusts for some of our other post-retirement benefit plans. These assets are managed by a third-party investment manager with oversight by management and are generally invested in equities, fixed-income securities and commingled funds comprised of equity and fixed-income securities. Our asset allocation strategy for the VEBA trusts considers potential fluctuations in our other post-retirement benefit obligation, the taxable nature of certain VEBA trusts, tax deduction limits on contributions and the regulatory environment. Our retirement plan assets are reported at fair value. See Note E for a discussion of the hierarchy for determining fair value. Our Level 1 assets include investments in publicly traded equity securities. These securities are actively traded and valued using quoted prices for identical securities from the market exchanges. Our Level 2 assets consist of fixed-income securities and commingled funds whose underlying investments are valued using observable marketplace inputs. The fair value of plan assets invested in fixed-income securities is generally determined under a market approach using valuation models that incorporate observable inputs such as interest rates, bond yields and quoted prices for similar assets. Our plan assets that are invested in commingled funds are valued using a unit price or net asset value (NAV) that is based on the underlying investments of the fund. Our Level 3 assets include real estate funds, insurance deposit contracts and direct private equity investments. Certain investments valued using NAV as a practical expedient are excluded from the fair value hierarchy. These investments are redeemable at NAV on a monthly or quarterly basis and have redemption notice periods of up to 90 days . The unfunded commitments related to these investments were not material on December 31, 2018 , and we had no unfunded commitments related to these investments on December 31, 2017 . The fair value of our pension plan assets by investment category and the corresponding level within the fair value hierarchy were as follows: Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Asset Category December 31, 2018 Cash and equivalents $ 73 $ — $ 73 $ — Equity securities (a): U.S. companies 732 732 — — Non-U.S. companies 117 117 — — Private equity investments 20 — — 20 Fixed-income securities: Corporate bonds (b) 1,600 — 1,600 — Treasury securities 1,410 — 1,410 — Commingled funds: Equity funds 5,243 — 5,243 — Fixed-income funds 624 — 624 — Real estate funds 68 — — 68 Other investments: Insurance deposit contracts 128 — — 128 Total plan assets in fair value hierarchy $ 10,015 $ 849 $ 8,950 $ 216 Plan assets measured using NAV as a practical expedient (c): Hedge funds 910 Real estate funds 420 Fixed-income funds 101 Equity funds 86 Total pension plan assets $ 11,532 (a) No single equity holding amounted to more than 1% of the total fair value. (b) Our corporate bond investments had an average rating of A+ . (c) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Asset Category December 31, 2017 Cash and equivalents $ 48 $ — $ 48 $ — Equity securities (a): U.S. companies 770 770 — — Non-U.S. companies 97 97 — — Private equity investments 18 — — 18 Fixed-income securities: Corporate bonds (b) 1,604 — 1,604 — Treasury securities 1,361 — 1,361 — Commingled funds: Equity funds 5,018 — 5,018 — Fixed-income funds 325 — 325 — Real estate funds 51 — — 51 Other investments: Insurance deposit contracts 120 — — 120 Total plan assets in fair value hierarchy $ 9,412 $ 867 $ 8,356 $ 189 Plan assets measured using NAV as a practical expedient (c): Real estate funds 390 Hedge funds 328 Total pension plan assets $ 10,130 (a) No single equity holding amounted to more than 1% of the total fair value. (b) Our corporate bond investments had an average rating of A+ . (c) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. The fair value of our other post-retirement benefit plan assets by category and the corresponding level within the fair value hierarchy were as follows: Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Asset Category (a) December 31, 2018 Cash and equivalents $ 23 $ — $ 23 Equity securities 80 80 — Fixed-income securities 87 — 87 Commingled funds: Equity funds 237 — 237 Fixed-income funds 111 — 111 Real estate funds 2 2 — Total plan assets in fair value hierarchy $ 540 $ 82 $ 458 Plan assets measured using NAV as a practical expedient (b): Hedge funds 22 Equity funds 3 Fixed-income funds 3 Real estate funds 2 Total other post-retirement benefit plan assets $ 570 (a) We had no Level 3 investments on December 31, 2018 . (b) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Asset Category (a) December 31, 2017 Cash and equivalents $ 18 $ — $ 18 Equity securities 70 70 — Fixed-income securities 89 — 89 Commingled funds: Equity funds 260 — 260 Fixed-income funds 99 — 99 Real estate funds 2 2 — Total plan assets in fair value hierarchy $ 538 $ 72 $ 466 Plan assets measured using NAV as a practical expedient (b): Real estate funds 2 Hedge funds 1 Total other post-retirement benefit plan assets $ 541 (a) We had no Level 3 investments on December 31, 2017 . (b) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. Changes in our Level 3 retirement plan assets during 2018 and 2017 were as follows: Private Equity Investments Real Estate Funds Insurance Deposits Contracts Total Level 3 Assets December 31, 2016 $ 13 $ 42 $ 109 $ 164 Actual return on plan assets: Unrealized gains, net 1 4 4 9 Realized gains, net — — 2 2 Purchases, sales and settlements, net 4 5 5 14 December 31, 2017 18 51 120 189 Actual return on plan assets: Unrealized losses, net — (1 ) — (1 ) Realized gains, net — — 3 3 Purchases, sales and settlements, net 2 18 5 25 December 31, 2018 $ 20 $ 68 $ 128 $ 216

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION We have five operating segments: Aerospace, Combat Systems, Information Technology, Mission Systems, and Marine Systems. We organize our segments in accordance with the nature of products and services offered. We measure each segment’s profitability based on operating earnings. As a result, we do not allocate net interest, other income and expense items, and income taxes to our segments. Summary financial information for each of our segments follows: Revenue Operating Earnings Revenue from U.S. Government Year Ended December 31 2018 2017 2016 2018 2017 2016 2018 2017 2016 Aerospace $ 8,455 $ 8,129 $ 7,815 $ 1,490 $ 1,577 $ 1,394 $ 334 $ 231 $ 361 Combat Systems 6,241 5,949 5,530 962 937 831 3,228 3,084 2,614 Information Technology 8,269 4,410 4,428 608 373 340 8,025 4,164 4,147 Mission Systems 4,726 4,481 4,716 659 638 601 3,774 3,629 3,837 Marine Systems 8,502 8,004 8,072 761 685 595 8,245 7,913 7,717 Corporate — — — (23 ) 26 (17 ) — — — Total $ 36,193 $ 30,973 $ 30,561 $ 4,457 $ 4,236 $ 3,744 $ 23,606 $ 19,021 $ 18,676 Corporate operating results have two primary components: pension and other post-retirement benefit income, and stock option expense. ASU 2017-07 requires the non-service cost components of pension and other post-retirement benefit cost (e.g., interest cost) to be reported in other income (expense) in the Consolidated Statement of Earnings. In our defense segments, as described in Note Q, pension and other post-retirement benefit costs are allocable contract costs. For these segments, we report the offset for the non-service cost components in Corporate operating results. Corporate operating results in 2018 also included one-time charges of approximately $45 associated with the costs to complete the CSRA acquisition. The following is additional summary financial information for each of our segments: Identifiable Assets Capital Expenditures Depreciation and Amortization Year Ended December 31 2018 2017 2016 2018 2017 2016 2018 2017 2016 Aerospace $ 11,220 $ 10,126 $ 9,792 $ 194 $ 132 $ 125 $ 154 $ 147 $ 153 Combat Systems 9,853 9,846 8,885 91 84 71 87 86 86 Information Technology 14,159 3,021 2,778 62 16 10 333 32 42 Mission Systems 5,984 5,856 5,667 49 47 87 65 60 61 Marine Systems 3,130 2,906 3,063 243 123 92 116 109 105 Corporate* 1,062 3,291 2,987 51 26 7 8 7 6 Total $ 45,408 $ 35,046 $ 33,172 $ 690 $ 428 $ 392 $ 763 $ 441 $ 453 * Corporate identifiable assets are primarily cash and equivalents. See Note C for additional revenue information by segment. The following table presents our revenue by geographic area based on the location of our customers: Year Ended December 31 2018 2017 2016 North America: United States $ 28,578 $ 23,519 $ 23,160 Other 755 915 709 Total North America 29,333 24,434 23,869 Europe 2,772 2,558 2,152 Asia/Pacific 2,252 2,011 1,650 Africa/Middle East 1,565 1,655 2,617 South America 271 315 273 Total revenue $ 36,193 $ 30,973 $ 30,561 Our revenue from non-U.S. operations was $4.2 billion in 2018 and $3.7 billion in 2017 and 2016 , and earnings from continuing operations before income taxes from non-U.S. operations were $578 in 2018 , $550 in 2017 and $530 in 2016 . The long-lived assets associated with these operations were 3% of our total long-lived assets on December 31, 2018 , and 5% for December 31, 2017 and 2016.

Condensed Consolidating Financi

Condensed Consolidating Financial Statements	12 Months Ended
	Dec. 31, 2018
Consolidating Financial Statements [Abstract]
Condensed Consolidating Financial Statements	CONDENSED CONSOLIDATING FINANCIAL STATEMENTS The fixed- and floating-rate notes described in Note K are fully and unconditionally guaranteed on an unsecured, joint and several basis by several of our 100 %-owned subsidiaries (the guarantors). The following condensed consolidating financial statements illustrate the composition of the parent, the guarantors on a combined basis (each guarantor together with its majority-owned subsidiaries) and all other subsidiaries on a combined basis. CONDENSED CONSOLIDATING STATEMENT OF EARNINGS Year Ended December 31, 2018 Parent Guarantors on a Combined Basis Other Subsidiaries Consolidating Adjustments Total Consolidated Revenue $ — $ 28,132 $ 8,061 $ — $ 36,193 Cost of sales 67 (22,841 ) (6,704 ) — (29,478 ) G&A (90 ) (1,638 ) (530 ) — (2,258 ) Operating earnings (23 ) 3,653 827 — 4,457 Interest, net (326 ) — (30 ) — (356 ) Other, net (81 ) 12 53 — (16 ) Earnings before income tax (430 ) 3,665 850 — 4,085 Provision for income tax, net 116 (677 ) (166 ) — (727 ) Discontinued operations, net of tax (13 ) — — — (13 ) Equity in net earnings of subsidiaries 3,672 — — (3,672 ) — Net earnings $ 3,345 $ 2,988 $ 684 $ (3,672 ) $ 3,345 Comprehensive income $ 3,025 $ 2,992 $ 305 $ (3,297 ) $ 3,025 Year Ended December 31, 2017 Revenue $ — $ 26,933 $ 4,040 $ — $ 30,973 Cost of sales 76 (21,695 ) (3,112 ) — (24,731 ) G&A (48 ) (1,643 ) (315 ) — (2,006 ) Operating earnings 28 3,595 613 — 4,236 Interest, net (97 ) 1 (7 ) — (103 ) Other, net (72 ) 12 4 — (56 ) Earnings before income tax (141 ) 3,608 610 — 4,077 Provision for income tax, net 154 (1,262 ) (57 ) — (1,165 ) Equity in net earnings of subsidiaries 2,899 — — (2,899 ) — Net earnings $ 2,912 $ 2,346 $ 553 $ (2,899 ) $ 2,912 Comprehensive income $ 3,479 $ 2,336 $ 1,158 $ (3,494 ) $ 3,479 Year Ended December 31, 2016 Revenue $ — $ 26,573 $ 3,988 $ — $ 30,561 Cost of sales 21 (21,811 ) (3,106 ) — (24,896 ) G&A (37 ) (1,568 ) (316 ) — (1,921 ) Operating earnings (16 ) 3,194 566 — 3,744 Interest, net (91 ) (2 ) 2 — (91 ) Other, net (11 ) 5 9 — 3 Earnings before income tax (118 ) 3,197 577 — 3,656 Provision for income tax, net 121 (1,055 ) (43 ) — (977 ) Discontinued operations, net of tax (107 ) — — — (107 ) Equity in net earnings of subsidiaries 2,676 — — (2,676 ) — Net earnings $ 2,572 $ 2,142 $ 534 $ (2,676 ) $ 2,572 Comprehensive income $ 2,468 $ 2,112 $ 543 $ (2,655 ) $ 2,468 CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2018 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated ASSETS Current assets: Cash and equivalents $ 460 $ — $ 503 $ — $ 963 Accounts receivable — 1,171 2,588 — 3,759 Unbilled receivables — 2,758 3,818 — 6,576 Inventories — 5,855 122 — 5,977 Other current assets (45 ) 441 518 — 914 Total current assets 415 10,225 7,549 — 18,189 Noncurrent assets: PP&E 273 7,197 1,933 — 9,403 Accumulated depreciation of PP&E (83 ) (4,075 ) (897 ) — (5,055 ) Intangible assets, net — 251 2,334 — 2,585 Goodwill — 8,031 11,563 — 19,594 Other assets 195 258 239 — 692 Net investment in subsidiaries 25,313 — — (25,313 ) — Total noncurrent assets 25,698 11,662 15,172 (25,313 ) 27,219 Total assets $ 26,113 $ 21,887 $ 22,721 $ (25,313 ) $ 45,408 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities: Short-term debt and current portion of long-term debt $ 850 $ — $ 123 $ — $ 973 Customer advances and deposits — 4,541 2,729 — 7,270 Other current liabilities 552 3,944 2,000 — 6,496 Total current liabilities 1,402 8,485 4,852 — 14,739 Noncurrent liabilities: Long-term debt 11,398 39 7 — 11,444 Other liabilities 1,581 4,073 1,839 — 7,493 Total noncurrent liabilities 12,979 4,112 1,846 — 18,937 Total shareholders’ equity 11,732 9,290 16,023 (25,313 ) 11,732 Total liabilities and shareholders’ equity $ 26,113 $ 21,887 $ 22,721 $ (25,313 ) $ 45,408 CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2017 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated ASSETS Current assets: Cash and equivalents $ 1,930 $ — $ 1,053 $ — $ 2,983 Accounts receivable — 1,259 2,358 — 3,617 Unbilled receivables — 2,547 2,693 — 5,240 Inventories — 5,216 87 — 5,303 Other current assets 351 461 373 — 1,185 Total current assets 2,281 9,483 6,564 — 18,328 Noncurrent assets: PP&E 221 6,779 1,237 — 8,237 Accumulated depreciation of PP&E (75 ) (3,869 ) (776 ) — (4,720 ) Intangible assets, net — 287 415 — 702 Goodwill — 8,320 3,594 — 11,914 Other assets 199 232 154 — 585 Net investment in subsidiaries 15,771 — — (15,771 ) — Total noncurrent assets 16,116 11,749 4,624 (15,771 ) 16,718 Total assets $ 18,397 $ 21,232 $ 11,188 $ (15,771 ) $ 35,046 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities: Short-term debt and current portion of long-term debt $ — $ 1 $ 1 $ — $ 2 Customer advances and deposits — 4,180 2,812 — 6,992 Other current liabilities 561 3,758 1,786 — 6,105 Total current liabilities 561 7,939 4,599 — 13,099 Noncurrent liabilities: Long-term debt 3,950 21 9 — 3,980 Other liabilities 2,451 3,473 608 — 6,532 Total noncurrent liabilities 6,401 3,494 617 — 10,512 Total shareholders’ equity 11,435 9,799 5,972 (15,771 ) 11,435 Total liabilities and shareholders’ equity $ 18,397 $ 21,232 $ 11,188 $ (15,771 ) $ 35,046 CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2018 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated Net cash provided by operating activities* $ (579 ) $ 2,954 $ 773 $ — $ 3,148 Cash flows from investing activities: Business acquisitions, net of cash acquired (9,749 ) (74 ) (276 ) — (10,099 ) Capital expenditures (51 ) (513 ) (126 ) — (690 ) Proceeds from sales of assets 90 472 — — 562 Other, net 4 (12 ) 1 — (7 ) Net cash used by investing activities (9,706 ) (127 ) (401 ) — (10,234 ) Cash flows from financing activities: Proceeds from fixed-rate notes 6,461 — — — 6,461 Purchases of common stock (1,769 ) — — — (1,769 ) Dividends paid (1,075 ) — — — (1,075 ) Proceeds from floating-rate notes 1,000 — — — 1,000 Proceeds from commercial paper, net 851 — — — 851 Repayment of CSRA accounts receivable purchase agreement — — (450 ) — (450 ) Other, net 2 35 31 — 68 Net cash provided by financing activities 5,470 35 (419 ) — 5,086 Net cash used by discontinued operations (20 ) — — — (20 ) Cash sweep/funding by parent 3,365 (2,862 ) (503 ) — — Net decrease in cash and equivalents (1,470 ) — (550 ) — (2,020 ) Cash and equivalents at beginning of year 1,930 — 1,053 — 2,983 Cash and equivalents at end of year $ 460 $ — $ 503 $ — $ 963 Year Ended December 31, 2017 Net cash provided by operating activities* $ 312 $ 2,371 $ 1,193 $ — $ 3,876 Cash flows from investing activities: Capital expenditures (26 ) (330 ) (72 ) — (428 ) Business acquisitions, net of cash acquired — (350 ) (49 ) — (399 ) Other, net 10 31 (2 ) — 39 Net cash used by investing activities (16 ) (649 ) (123 ) — (788 ) Cash flows from financing activities: Purchases of common stock (1,558 ) — — — (1,558 ) Dividends paid (986 ) — — — (986 ) Proceeds from fixed-rate notes 985 — — — 985 Repayment of fixed-rate notes (900 ) — — — (900 ) Other, net 63 (3 ) — — 60 Net cash used by financing activities (2,396 ) (3 ) — — (2,399 ) Net cash used by discontinued operations (40 ) — — — (40 ) Cash sweep/funding by parent 2,816 (1,719 ) (1,097 ) — — Net increase in cash and equivalents 676 — (27 ) — 649 Cash and equivalents at beginning of year 1,254 — 1,080 — 2,334 Cash and equivalents at end of year $ 1,930 $ — $ 1,053 $ — $ 2,983 * Continuing operations only. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2016 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated Net cash provided by operating activities* $ 217 $ 1,881 $ 65 $ — $ 2,163 Cash flows from investing activities: Capital expenditures (8 ) (336 ) (48 ) — (392 ) Other, net 7 32 (38 ) — 1 Net cash used by investing activities (1 ) (304 ) (86 ) — (391 ) Cash flows from financing activities: Purchases of common stock (1,996 ) — — — (1,996 ) Proceeds from fixed-rate notes 992 — — — 992 Dividends paid (911 ) — — — (911 ) Repayment of fixed-rate notes (500 ) — — — (500 ) Proceeds from stock option exercises 292 — — — 292 Other, net (45 ) (1 ) — — (46 ) Net cash used by financing activities (2,168 ) (1 ) — — (2,169 ) Net cash used by discontinued operations (54 ) — — — (54 ) Cash sweep/funding by parent 1,528 (1,576 ) 48 — — Net decrease in cash and equivalents (478 ) — 27 — (451 ) Cash and equivalents at beginning of year 1,732 — 1,053 — 2,785 Cash and equivalents at end of year $ 1,254 $ — $ 1,080 $ — $ 2,334 * Continuing operations only.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Segment Information	Concurrent with the acquisition, for segment reporting purposes, we reorganized our Information Systems and Technology operating segment into two separate segments: Information Technology and Mission Systems. Our company now has five operating segments: Aerospace, Combat Systems, Information Technology, Mission Systems and Marine Systems. The latter four segments we collectively refer to as our defense segments. Prior-period segment information has been restated for this change. We organize our segments in accordance with the nature of products and services offered. We measure each segment’s profitability based on operating earnings. As a result, we do not allocate net interest, other income and expense items, and income taxes to our segments.
Basis of Consolidation and Classification	Basis of Consolidation and Classification. The Consolidated Financial Statements include the accounts of General Dynamics Corporation and our wholly owned and majority-owned subsidiaries. We eliminate all inter-company balances and transactions in the Consolidated Financial Statements. Some prior-year amounts have been reclassified among financial statement accounts or disclosures to conform to the current-year presentation. Consistent with industry practice, we classify assets and liabilities related to long-term contracts as current, even though some of these amounts may not be realized within one year.
Use of Estimates	Use of Estimates. The nature of our business requires that we make estimates and assumptions in accordance with U.S. generally accepted accounting principles (GAAP). These estimates and assumptions affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenue and expenses during the reporting period . We base our estimates on historical experience, currently available information and various other assumptions that we believe are reasonable under the circumstances . Actual results could differ from these estimates.
Discontinued Operations, Net of Tax	Discontinued Operations, Net of Tax. Concurrent with the acquisition of CSRA, we were required by a government customer to dispose of certain CSRA operations to address an organizational conflict of interest with respect to services provided to the customer. In 2018, we sold these operations. In accordance with GAAP, the sale did not result in a gain for financial reporting purposes. However, the sale generated a taxable gain, resulting in tax expense of $13 . In 2013, we settled litigation with the U.S. Navy related to the terminated A-12 aircraft contract in the company’s former tactical military aircraft business. In connection with the settlement, we released some rights to reimbursement of costs on ships under contract at our Bath, Maine, shipyard. As we progressed through the shipbuilding process, we determined that the cost associated with this settlement was greater than anticipated. Therefore, in 2016, we recognized an $84 loss, net of tax, to adjust the previously recognized settlement value. In addition, we recognized $23 of losses, net of tax, in 2016 related to other former operations of the company.
Research and Development Expenses	Research and Development Expenses. Company-sponsored research and development (R&D) expenses, including product development costs, were $502 in 2018 , $521 in 2017 and $418 in 2016 . The R&D expenses in 2018 and 2017 reflected ongoing product-development efforts in the Aerospace segment as we progressed with the certification of our two newest Gulfstream aircraft models, the G500 and G600. R&D expenses are included in operating costs and expenses in the Consolidated Statement of Earnings in the period in which they are incurred. Customer-sponsored R&D expenses are charged directly to the related contracts. The Aerospace segment has cost-sharing arrangements with some of its suppliers that enhance the segment’s internal development capabilities and offset a portion of the financial cost associated with the segment’s product development efforts. These arrangements explicitly state that supplier contributions are for reimbursements of costs we incur in the development of new aircraft models and technologies, and we retain substantial rights in the products developed under these arrangements. We record amounts received from these cost-sharing arrangements as a reduction of R&D expenses. We have no obligation to refund any amounts received under the agreements regardless of the outcome of the development efforts. Under the typical terms of an agreement, payments received from suppliers for their share of the costs are based on milestones and are recognized as received. Our policy is to defer payments in excess of the costs we have incurred.
Cash And Equivalents And Investments In Debt And Equity Securities	Cash and Equivalents and Investments in Debt and Equity Securities. We consider securities with a maturity of three months or less to be cash equivalents. Our cash balances are invested primarily in time deposits rated A-/A3 or higher. Our investments in other securities are included in other current and noncurrent assets on the Consolidated Balance Sheet (see Note E). We report our equity securities at fair value with subsequent changes in fair value recognized in net earnings. We report our available-for-sale debt securities at fair value with unrealized gains and losses recognized as a component of other comprehensive income in the Consolidated Statement of Comprehensive Income.
Other Contract Costs	Other Contract Costs. Other contract costs represent amounts that are not currently allocable to government contracts, such as a portion of our estimated workers’ compensation obligations, other insurance-related assessments, pension and other post-retirement benefits, and environmental expenses. These costs will become allocable to contracts generally after they are paid. We expect to recover these costs through ongoing business, including existing backlog and probable follow-on contracts. If the backlog in the future does not support the continued deferral of these costs, the profitability of our remaining contracts could be adversely affected.
Long-lived Assets and Goodwill	Long-lived Assets and Goodwill. We review long-lived assets, including intangible assets subject to amortization, for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. We assess the recoverability of the carrying value of assets held for use based on a review of undiscounted projected cash flows. Impairment losses, where identified, are measured as the excess of the carrying value of the long-lived asset over its estimated fair value as determined by discounted projected cash flows. Concurrent with the acquisition of CSRA in April 2018, we reorganized our Information Systems and Technology operating segment in accordance with the nature of the segment’s products and services into the Information Technology and Mission Systems segments. This reorganization similarly changed the composition of our reporting units. Accordingly, goodwill of the Information Systems and Technology reporting unit was reassigned to the Information Technology and Mission Systems reporting units using a relative fair value allocation approach as of the date of the reorganization. We review goodwill for impairment annually or when circumstances indicate that the likelihood of an impairment is greater than 50%. Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired in a business combination. The test for goodwill impairment is a two-step process to first identify potential goodwill impairment for each reporting unit by comparing the fair value of each of our reporting units to its respective carrying value and then, if necessary, measure the amount of the impairment loss. Our reporting units are consistent with our operating segments in Note R . We estimate the fair value of our reporting units based primarily on the discounted projected cash flows of the underlying operations. We completed the required annual goodwill impairment test as of December 31, 2018 . The results of the first-step test indicated that, for each of our reporting units, no impairment existed. The estimated fair value of each of our reporting units was substantially in excess of its respective carrying value as of December 31, 2018 , with the exception of our Information Technology reporting unit . The estimated fair value of the Information Technology reporting unit exceeded its carrying value as of December 31, 2018 , by slightly more than 5% . This is due to the significant size of the CSRA acquisition relative to the newly formed Information Technology reporting unit and its recent acquisition date. Given that the net book value of this business was recorded at its fair value during the current reporting period, the reporting unit’s carrying value, by default, closely approximates its fair value at year end. As the carrying value and fair value of the Information Technology reporting unit are closely aligned, a material change in the fair value or carrying value would put the reporting unit at risk of goodwill impairment. For example, our ability to realize synergies from the acquisition of CSRA and the level of funding in the U.S. government budget for contracts in our portfolio are key assumptions in our projections of revenue, earnings and cash flows. If our actual experience in future years falls significantly below our current projections, the fair value of the reporting unit could be negatively impacted. Similarly, an increase in interest rates would lower our discounted cash flows and negatively impact the fair value of the reporting unit. We believe the projections and assumptions we used in estimating fair value are reasonable, but it is possible they could change, impacting our fair value estimate, or the carrying value could change.
Accounting Standards Updates	Accounting Standards Updates. On January 1, 2018, we adopted the following accounting standards issued by the Financial Accounting Standards Board (FASB): • ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Specific to our business, ASU 2016-01 requires equity investments to be measured at fair value with changes in fair value recognized in net income. The ASU eliminates the available-for-sale classification for equity investments that recognized changes in fair value as a component of other comprehensive income. We adopted the standard on a modified retrospective basis on January 1, 2018, and recognized the cumulative effect as a $24 increase to retained earnings on the date of adoption. • ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. ASU 2016-15 is intended to reduce diversity in practice in how certain cash receipts and cash payments are presented and classified in the Consolidated Statement of Cash Flows by providing guidance on eight specific cash flow issues. We adopted the standard retrospectively on January 1, 2018. The adoption of the ASU did not have a material effect on our cash flows in 2017 and 2016. • ASU 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 the service cost component of net retirement benefit cost to be reported separately from the other components of net retirement benefit cost in the Consolidated Statement of Earnings. We adopted the standard retrospectively on January 1, 2018. Our restated operating earnings increased $59 and $10 in 2017 and 2016 , respectively, due to the reclassification of the non-service cost components of net benefit cost. Other income decreased by the same amount, with no impact to net earnings. • ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. ASU 2018-02 allows the reclassification from accumulated other comprehensive income to retained earnings of stranded tax effects resulting from the implementation of the Tax Cuts and Jobs Act (tax reform) enacted on December 22, 2017. We adopted the standard on January 1, 2018, and recognized a $614 increase to retained earnings on the date of adoption. There are several other accounting standards that have been issued by the FASB but are not effective until after December 31, 2018, including the following: • ASU 2016-02, Leases (Topic 842). ASU 2016-02 requires the recognition of lease rights and obligations as assets and liabilities on the balance sheet. Previously, lessees were not required to recognize on the balance sheet assets and liabilities arising from operating leases. The ASU also requires disclosure of key information about leasing arrangements. ASU 2016-02 is effective on January 1, 2019, using a modified retrospective method of adoption as of January 1, 2017. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements, which provides an alternative transition method of adoption, permitting the recognition of a cumulative-effect adjustment to retained earnings on the date of adoption in lieu of retrospective adoption. We are adopting the standard effective January 1, 2019, using the alternative transition method provided by ASU 2018-11. In order to adopt the new standard, we developed a comprehensive project plan and established cross-functional project teams to guide the implementation. The project plan included implementing a third-party software solution to facilitate the consolidation of our leases for reporting purposes, reviewing all forms of leases, performing a completeness assessment of our lease population, analyzing the optional practical expedients available in the new standard, and updating our business processes, systems and controls to meet the requirements of the new standard. The new standard provides several optional practical expedients for use in transition. We have elected to use what the FASB has deemed the “package of practical expedients,” which allows us not to reassess our previous conclusions about lease identification, lease classification and the accounting treatment for initial direct costs. We have not elected the practical expedients pertaining to the use of hindsight and land easements. The ASU also provides several optional practical expedients for the ongoing accounting for leases. We have elected the short-term lease recognition exemption for all leases that qualify, meaning that for these leases, we will not recognize right-of-use (ROU) assets or lease liabilities on our Consolidated Balance Sheet. Additionally, we have elected to use the practical expedient to not separate lease and non-lease components for leases of real estate, meaning that for these leases, the non-lease components are included in the associated ROU asset and lease liability balances on our Consolidated Balance Sheet. The most significant effects of the standard on our Consolidated Financial Statements are (1) the recognition of new ROU assets and lease liabilities on our Consolidated Balance Sheet for our operating leases, and (2) significant new disclosures about our leasing activities. We expect to recognize operating lease liabilities ranging from $1.2 to $1.6 billion , with corresponding ROU assets of the same amount based on the present value of the remaining lease payments over the lease term. The new standard is not expected to have a material impact on our results of operations or cash flows. • ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. ASU 2017-12 is intended to simplify hedge accounting by better aligning an entity’s financial reporting for hedging relationships with its risk management activities through the expansion of the types of financial and nonfinancial hedging strategies that are eligible for hedge accounting. The ASU also simplifies the application of the hedge accounting guidance, including eliminating the requirement to separately measure and report hedge ineffectiveness. For cash flow hedges existing at the adoption date, the standard requires adoption on a modified retrospective basis with a cumulative-effect adjustment to the Consolidated Balance Sheet as of the beginning of the year of adoption. The amendments to presentation guidance and disclosure requirements are required to be adopted prospectively. We adopted the standard on January 1, 2019. The adoption of the ASU did not have a material effect on our results of operations, financial condition or cash flows.
Revenue	The majority of our revenue is derived from long-term contracts and programs that can span several years. We account for revenue in accordance with Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers. Performance Obligations. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account in ASC Topic 606 . A contract’s transaction price is allocated to each distinct performance obligation within that contract and recognized as revenue when, or as, the performance obligation is satisfied. The majority of our contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and is, therefore, not distinct. Some of our contracts have multiple performance obligations, most commonly due to the contract covering multiple phases of the product lifecycle (development, production, maintenance and support). For contracts with multiple performance obligations, we allocate the contract’s transaction price to each performance obligation using our best estimate of the standalone selling price of each distinct good or service in the contract. The primary method used to estimate standalone selling price is the expected cost plus a margin approach, under which we forecast our expected costs of satisfying a performance obligation and then add an appropriate margin for that distinct good or service. Contract modifications are routine in the performance of our contracts. Contracts are often modified to account for changes in contract specifications or requirements. In most instances, contract modifications are for goods or services that are not distinct and, therefore, are accounted for as part of the existing contract. Our performance obligations are satisfied over time as work progresses or at a point in time. Revenue from products and services transferred to customers over time accounted for 74% of our revenue in 2018 , 71% in 2017 and 72% in 2016 . Substantially all of our revenue in the defense segments is recognized over time, because control is transferred continuously to our customers. Typically, revenue is recognized over time using costs incurred to date relative to total estimated costs at completion to measure progress toward satisfying our performance obligations. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contract costs include labor, material, overhead and, when appropriate, G&A expenses. Revenue from goods and services transferred to customers at a point in time accounted for 26% of our revenue in 2018 , 29% in 2017 and 28% in 2016 . The majority of our revenue recognized at a point in time is for the manufacture of business-jet aircraft in our Aerospace segment. Revenue on these contracts is recognized when the customer obtains control of the asset, which is generally upon delivery and acceptance by the customer of the fully outfitted aircraft. On December 31, 2018 , we had $67.9 billion of remaining performance obligations, which we also refer to as total backlog. We expect to recognize approximately 45% of our remaining performance obligations as revenue in 2019, an additional 35% by 2021 and the balance thereafter. On December 31, 2017 , we had $63.2 billion of remaining performance obligations, at which time we expected to recognize approximately 40% of these remaining performance obligations as revenue in 2018, an additional 40% by year-end 2020 and the balance thereafter. Contract Estimates. Accounting for long-term contracts and programs involves the use of various techniques to estimate total contract revenue and costs. For long-term contracts, we estimate the profit on a contract as the difference between the total estimated revenue and expected costs to complete a contract and recognize that profit over the life of the contract. Contract estimates are based on various assumptions to project the outcome of future events that often span several years. These assumptions include labor productivity and availability; the complexity of the work to be performed; the cost and availability of materials; the performance of subcontractors; and the availability and timing of funding from the customer. The nature of our contracts gives rise to several types of variable consideration, including claims and award and incentive fees. We include in our contract estimates additional revenue for submitted contract modifications or claims against the customer when we believe we have an enforceable right to the modification or claim, the amount can be estimated reliably and its realization is probable. In evaluating these criteria, we consider the contractual/legal basis for the claim, the cause of any additional costs incurred, the reasonableness of those costs and the objective evidence available to support the claim. We include award or incentive fees in the estimated transaction price when there is a basis to reasonably estimate the amount of the fee. These estimates are based on historical award experience, anticipated performance and our best judgment at the time. Because of our certainty in estimating these amounts, they are included in the transaction price of our contracts and the associated remaining performance obligations. As a significant change in one or more of these estimates could affect the profitability of our contracts, we review and update our contract-related estimates regularly. We recognize adjustments in estimated profit on contracts under the cumulative catch-up method. Under this method, the impact of the adjustment on profit recorded to date on a contract is recognized in the period the adjustment is identified. Revenue and profit in future periods of contract performance are recognized using the adjusted estimate. If at any time the estimate of contract profitability indicates an anticipated loss on the contract, we recognize the total loss in the period it is identified. The impact of adjustments in contract estimates on our operating earnings can be reflected in either operating costs and expenses or revenue. Our segments operate under fixed-price, cost-reimbursement and time-and-materials contracts. Our production contracts are primarily fixed-price. Under these contracts, we agree to perform a specific scope of work for a fixed amount. Contracts for research, engineering, repair and maintenance, and other services are typically cost-reimbursement or time-and-materials. Under cost-reimbursement contracts, the customer reimburses contract costs incurred and pays a fixed, incentive or award-based fee. These fees are determined by our ability to achieve targets set in the contract, such as cost, quality, schedule and performance. Under time-and-materials contracts, the customer pays a fixed hourly rate for direct labor and generally reimburses us for the cost of materials. Each of these contract types presents advantages and disadvantages. Typically, we assume more risk with fixed-price contracts. However, these types of contracts offer additional profits when we complete the work for less than originally estimated. Cost-reimbursement contracts generally subject us to lower risk. Accordingly, the associated base fees are usually lower than fees earned on fixed-price contracts. Under time-and-materials contracts, our profit may vary if actual labor-hour rates vary significantly from the negotiated rates. Also, because these contracts can provide little or no fee for managing material costs, the content mix can impact profitability. Contract Balances. The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities) on the Consolidated Balance Sheet. In our defense segments, amounts are billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals (e.g., biweekly or monthly) or upon achievement of contractual milestones. Generally, billing occurs subsequent to revenue recognition, resulting in contract assets. However, we sometimes receive advances or deposits from our customers, particularly on our international contracts, before revenue is recognized, resulting in contract liabilities. These assets and liabilities are reported on the Consolidated Balance Sheet on a contract-by-contract basis at the end of each reporting period. In our Aerospace segment, we generally receive deposits from customers upon contract execution and upon achievement of contractual milestones. These deposits are liquidated when revenue is recognized.
Earnings Per Share	Diluted EPS incorporates the additional shares issuable upon the assumed exercise of stock options and the release of restricted stock and restricted stock units (RSUs). We compute basic earnings per share (EPS) using net earnings for the period and the weighted average number of common shares outstanding during the period.
Fair Value of Financial Instruments	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between marketplace participants. Various valuation approaches can be used to determine fair value, each requiring different valuation inputs. The following hierarchy classifies the inputs used to determine fair value into three levels: • Level 1 - quoted prices in active markets for identical assets or liabilities; • Level 2 - inputs, other than quoted prices, observable by a marketplace participant either directly or indirectly; and • Level 3 - unobservable inputs significant to the fair value measurement. Our Level 1 assets include investments in publicly traded equity securities valued using quoted prices from the market exchanges. The fair value of our Level 2 assets and liabilities is determined under a market approach using valuation models that incorporate observable inputs such as interest rates, bond yields and quoted prices for similar assets. Our Level 3 assets include direct private equity investments that are measured using inputs unobservable to a marketplace participant. Our financial instruments include cash and equivalents, accounts receivable and payable, marketable securities held in trust and other investments, short- and long-term debt, and derivative financial instruments. The carrying values of cash and equivalents and accounts receivable and payable on the Consolidated Balance Sheet approximate their fair value.
Income Tax Provision	Income Tax Provision. We calculate our provision for federal, state and international income taxes based on current tax law. U.S. federal tax reform was enacted on December 22, 2017, and has several key provisions impacting the accounting for and reporting of income taxes. The most significant provision reduced the U.S. corporate statutory tax rate from 35% to 21% beginning on January 1, 2018.
Tax Uncertainties	Tax Uncertainties. For all periods open to examination by tax authorities, we periodically assess our liabilities and contingencies based on the latest available information. Where we believe there is more than a 50% chance that our tax position will not be sustained, we record our best estimate of the resulting tax liability, including interest, in the Consolidated Financial Statements. We include any interest or penalties incurred in connection with income taxes as part of income tax expense. The total amount of these tax liabilities on December 31, 2018 , was not material to our results of operations, financial condition or cash flows. We participate in the Internal Revenue Service (IRS) Compliance Assurance Process (CAP), a real-time audit of our consolidated federal corporate income tax return. The IRS has examined our consolidated federal income tax returns through 2017. We do not expect the resolution of tax matters for open years to have a material impact on our results of operations, financial condition, cash flows or effective tax rate. Based on all known facts and circumstances and current tax law, we believe the total amount of any unrecognized tax benefits on December 31, 2018 , was not material to our results of operations, financial condition or cash flows, and if recognized, would not have a material impact on our effective tax rate. In addition, there are no tax positions for which it is reasonably possible that the unrecognized tax benefits will vary significantly over the next 12 months, producing, individually or in the aggregate, a material effect on our results of operations, financial condition or cash flows.
Accounts and Unbilled Receivables	Accounts receivable represent amounts billed and currently due from customers. Payment is typically received from our customers either at periodic intervals (e.g., biweekly or monthly) or upon achievement of contractual milestones. Unbilled receivables represent revenue recognized on long-term contracts (contract costs and estimated profits) less associated advances and progress billings. These amounts will be billed in accordance with the agreed-upon contractual terms.
Inventories	The majority of our inventories are for business-jet aircraft. Our inventories are stated at the lower of cost or net realizable value. Work in process represents largely labor, material and overhead costs associated with aircraft in the manufacturing process and is based primarily on the estimated average unit cost in a production lot. Raw materials are valued primarily on the first-in, first-out method. We record pre-owned aircraft acquired in connection with the sale of new aircraft at the lower of the trade-in value or the estimated net realizable value.
Property, Plant and Equipment, Net	We depreciate most of our assets using the straight-line method and the remainder using accelerated methods. Buildings and improvements are depreciated over periods of up to 50 years . Machinery and equipment are depreciated over periods of up to 30 years . Property, plant and equipment (PP&E) is carried at historical cost, net of accumulated depreciation.
Derivative Financial Instruments and Hedging Activities	We are exposed to market risk, primarily from foreign currency exchange rates, interest rates, commodity prices and investments. We may use derivative financial instruments to hedge some of these risks as described below. We do not use derivative financial instruments for trading or speculative purposes. Foreign Currency Risk. Our foreign currency exchange rate risk relates to receipts from customers, payments to suppliers and inter-company transactions denominated in foreign currencies. To the extent possible, we include terms in our contracts that are designed to protect us from this risk. Otherwise, we enter into derivative financial instruments, principally foreign currency forward purchase and sale contracts, designed to offset and minimize our risk. The dollar-weighted two -year average maturity of these instruments generally matches the duration of the activities that are at risk. Interest Rate Risk. Our financial instruments subject to interest rate risk include variable-rate commercial paper and fixed- and floating-rate long-term debt obligations. As described in Note K, we entered into derivative financial instruments, specifically interest rate swap contracts, to eliminate our floating-rate interest rate risk . The interest rate risk associated with our financial instruments is not material. Commodity Price Risk. We are subject to rising labor and commodity price risk, primarily on long-term, fixed-price contracts. To the extent possible, we include terms in our contracts that are designed to protect us from these risks. Some of the protective terms included in our contracts are considered derivative financial instruments but are not accounted for separately, because they are clearly and closely related to the host contract. We have not entered into any material commodity hedging contracts but may do so as circumstances warrant. We do not believe that changes in labor or commodity prices will have a material impact on our results of operations or cash flows. Hedging Activities. We had notional forward exchange and interest rate swap contracts outstanding of $5.8 billion and $4.3 billion on December 31, 2018 and 2017 , respectively. These derivative financial instruments are cash flow hedges, and are reflected at fair value on the Consolidated Balance Sheet in other current assets and liabilities. See Note E for additional details. Changes in fair value (gains and losses) related to derivative financial instruments that qualify as cash flow hedges are deferred in AOCL until the underlying transaction is reflected in earnings. Gains and losses on derivative financial instruments that do not qualify for hedge accounting are recorded each period in the Consolidated Statement of Earnings in operating costs and expenses or interest expense. The gains and losses on derivative financial instruments that do not qualify for hedge accounting generally offset losses and gains on the assets and liabilities being hedged. Gains and losses resulting from hedge ineffectiveness are recognized in the Consolidated Statement of Earnings for all derivative financial instruments, regardless of designation.
Foreign Currency and Financial Statement Translation	Foreign Currency Financial Statement Translation. We translate foreign currency balance sheets from our international businesses’ functional currency (generally the respective local currency) to U.S. dollars at the end-of-period exchange rates, and statements of earnings at the average exchange rates for each period. The resulting foreign currency translation adjustments are a component of AOCL. We do not hedge the fluctuation in reported revenue and earnings resulting from the translation of these international operations’ results into U.S. dollars. The impact of translating our non-U.S. operations’ revenue into U.S. dollars was not material to our results of operations in any of the past three years. In addition, the effect of changes in foreign exchange rates on non-U.S. cash balances was not material in any of the past three years.
Commitments and Contingencies	In addition, from time to time and in the ordinary course of business, we contractually guarantee the payment or performance of our subsidiaries arising under certain contracts. Aircraft Trade-ins. In connection with orders for new aircraft in contract backlog, our Aerospace segment has outstanding options with some customers to trade in aircraft as partial consideration in their new-aircraft transaction. These trade-in commitments are generally structured to establish the fair market value of the trade-in aircraft at a date generally 45 or fewer days preceding delivery of the new aircraft to the customer. At that time, the customer is required to either exercise the option or allow its expiration. Additionally, certain trade-in commitments are structured to guarantee a pre-determined trade-in value. In either case, any excess of the pre-established trade-in price above the fair market value at the time the new aircraft is delivered is treated as a reduction of revenue in the new-aircraft sales transaction. Other Government Contracts. As a government contractor, we are subject to U.S. government audits and investigations relating to our operations, including claims for fines, penalties, and compensatory and treble damages. We believe the outcome of such ongoing government audits and investigations will not have a material impact on our results of operations, financial condition or cash flows. In the performance of our contracts, we routinely request contract modifications that require additional funding from the customer. Most often, these requests are due to customer-directed changes in the scope of work. While we are entitled to recovery of these costs under our contracts, the administrative process with our customer may be protracted. Based on the circumstances, we periodically file requests for equitable adjustment (REAs) that are sometimes converted into claims. In some cases, these requests are disputed by our customer. We believe our outstanding modifications, REAs and other claims will be resolved without material impact to our results of operations, financial condition or cash flows. Letters of Credit and Guarantees. In the ordinary course of business, we have entered into letters of credit, bank guarantees, surety bonds and other similar arrangements with financial institutions and insurance carriers Environmental We are subject to and affected by a variety of federal, state, local and foreign environmental laws and regulations. We are directly or indirectly involved in environmental investigations or remediation at some of our current and former facilities and third-party sites that we do not own but where we have been designated a Potentially Responsible Party (PRP) by the U.S. Environmental Protection Agency or a state environmental agency. Based on historical experience, we expect that a significant percentage of the total remediation and compliance costs associated with these facilities will continue to be allowable contract costs and, therefore, recoverable under U.S. government contracts. As required, we provide financial assurance for certain sites undergoing or subject to investigation or remediation. We accrue environmental costs when it is probable that a liability has been incurred and the amount can be reasonably estimated. Where applicable, we seek insurance recovery for costs related to environmental liabilities. We do not record insurance recoveries before collection is considered probable. Based on all known facts and analyses, we do not believe that our liability at any individual site, or in the aggregate, arising from such environmental conditions will be material to our results of operations, financial condition or cash flows. We also do not believe that the range of reasonably possible additional loss beyond what has been recorded would be material to our results of operations, financial condition or cash flows.
Product Warranties	Product Warranties. We provide warranties to our customers associated with certain product sales. We record estimated warranty costs in the period in which the related products are delivered. The warranty liability recorded at each balance sheet date is based generally on the number of months of warranty coverage remaining for the products delivered and the average historical monthly warranty payments. Warranty obligations incurred in connection with long-term production contracts are accounted for within the contract estimates at completion. Our other warranty obligations, primarily for business-jet aircraft, are included in other current and noncurrent liabilities on the Consolidated Balance Sheet.
Equity Compensation Plans	Equity-based Compensation Expense. Equity-based compensation expense is included in G&A expenses. Stock Options. Stock options granted under our equity compensation plans are issued with an exercise price at the fair value of our common stock determined by the average of the high and low stock prices as listed on the New York Stock Exchange on the date of grant. The majority of our outstanding stock options vest over three years, with 50% of the options vesting after two years and the remaining 50% vesting the following year, and expire 10 years after the grant date. Equity Compensation Overview. We have equity compensation plans for employees, as well as for non-employee members of our board of directors. The equity compensation plans seek to provide an effective means of attracting and retaining directors, officers and key employees, and to provide them with incentives to enhance our growth and profitability. Under the equity compensation plans, awards may be granted to officers, employees or non-employee directors in common stock, options to purchase common stock, restricted shares of common stock, participation units or any combination of these. Annually, we grant awards of stock options, restricted stock and RSUs to participants in our equity compensation plans in early March. Additionally, we may make limited ad hoc grants on a quarterly basis for new hires or promotions. We issue common stock under our equity compensation plans from treasury stock. We recognize compensation expense related to stock options on a straight-line basis over the vesting period of the awards, net of estimated forfeitures. Estimated forfeitures are based on our historical forfeiture experience. We estimate the fair value of stock options on the date of grant using the Black-Scholes option pricing model Restricted Stock/RSUs. The fair value of restricted stock and RSUs equals the average of the high and low market prices of our common stock as listed on the New York Stock Exchange on the date of grant. Grants of restricted stock are awards of shares of common stock. Participation units represent obligations that have a value derived from or related to the value of our common stock. These include stock appreciation rights, phantom stock units and RSUs, and are payable in cash or common stock. Restricted stock and RSUs generally vest over a three -year restriction period after the grant date, during which recipients may not sell, transfer, pledge, assign or otherwise convey their restricted shares to another party. During this period, restricted stock recipients receive cash dividends on their restricted shares and are entitled to vote those shares, while RSU recipients receive dividend-equivalent units instead of cash dividends and are not entitled to vote their RSUs or dividend-equivalent units. We grant RSUs with a performance measure derived from a non-GAAP-based management metric, return on invested capital (ROIC). Depending on the company’s performance with respect to this metric, the number of RSUs earned may be less than, equal to or greater than the original number of RSUs awarded subject to a payout range. We generally recognize compensation expense related to restricted stock and RSUs on a straight-line basis over the vesting period
Retirement Plans	Plan Assets A committee of our board of directors is responsible for the strategic oversight of our defined-benefit retirement plan assets held in trust. Management develops investment policies and provides oversight of a third-party investment manager who reports to the committee on a regular basis. The outsourced third-party investment manager develops investment strategies and makes all day-to-day investment decisions related to defined-benefit retirement plan assets in accordance with our investment policy and target allocation percentages. Our investment policy endeavors to strike the appropriate balance among capital preservation, asset growth and current income. The objective of our investment policy is to generate future returns consistent with our assumed long-term rates of return used to determine our benefit obligations and net annual benefit cost. Target allocation percentages vary over time depending on the perceived risk and return potential of various asset classes and market conditions. We provide defined-contribution benefits to eligible employees, as well as some remaining defined-benefit pension and other post-retirement benefits. Substantially all of our plans use a December 31 measurement date consistent with our fiscal year. The following discussion reflects the inclusion of legacy CSRA plans assumed in connection with the acquisition as of the acquisition date. Retirement Plan Summary Information Defined-contribution Benefits. We provide eligible employees the opportunity to participate in defined-contribution savings plans (commonly known as 401(k) plans), which permit contributions on a before-tax and after-tax basis. Employees may contribute to various investment alternatives. In most of these plans, we match a portion of the employees’ contributions. Retirement Plan Assumptions We calculate the plan assets and liabilities for a given year and the net annual benefit cost for the subsequent year using assumptions determined as of December 31 of the year in question. We base the discount rates on a current yield curve developed from a portfolio of high-quality, fixed-income investments with maturities consistent with the projected benefit payout period. We use the spot rate approach to identify individual spot rates along the yield curve that correspond with the timing of each projected service cost and discounted benefit obligation payment. We determine the long-term rates of return on assets based on consideration of historical and forward-looking returns and the current and expected asset allocation strategy. In 2017, we decreased the expected long-term rate of return on assets in our primary U.S. government and commercial pension plans by 75 basis points following an assessment of the historical and expected long-term returns of our various asset classes. Beginning in 2019, we will decrease the expected long-term rates of return on assets in our primary U.S. other post-retirement benefit plans by 100 basis points, following an assessment of the historical and expected long-term returns of our various asset classes. This decrease is not expected to have a material impact on our 2019 benefit costs. Retirement plan assumptions are based on our best judgment, including consideration of current and future market conditions. Changes in these estimates impact future pension and other post-retirement benefit cost. As discussed above, we defer recognition of the cumulative benefit cost for our government plans in excess of costs allocated to contracts and included in revenue. Therefore, the impact of annual changes in financial reporting assumptions on the cost for these plans does not immediately affect our operating results. Approximately 75% of our pension plan assets are held in a single trust for our primary U.S. government and commercial pension plans. On December 31, 2018 , the trust was invested largely in publicly traded equities, fixed-income securities and commingled funds comprised of equity securities. The trust also invests in other asset classes consistent with our investment policy. Our investments in equity assets include U.S. and international securities and equity funds. Our investments in fixed-income assets include U.S. Treasury and U.S. agency securities, corporate bonds, mortgage-backed securities and other asset-backed securities. Our investment policy allows the use of derivative instruments when appropriate to reduce anticipated asset volatility, to gain exposure to an asset class or to adjust the duration of fixed-income assets. Assets for our non-U.S. pension plans are held in trusts in the countries in which the related operations reside. Our non-U.S. operations maintain investment policies for their individual plans based on country-specific regulations. The non-U.S. plan assets are invested primarily in commingled funds comprised of equity and fixed-income securities. We hold assets in VEBA trusts for some of our other post-retirement benefit plans. These assets are managed by a third-party investment manager with oversight by management and are generally invested in equities, fixed-income securities and commingled funds comprised of equity and fixed-income securities. Our asset allocation strategy for the VEBA trusts considers potential fluctuations in our other post-retirement benefit obligation, the taxable nature of certain VEBA trusts, tax deduction limits on contributions and the regulatory environment. Our retirement plan assets are reported at fair value. See Note E for a discussion of the hierarchy for determining fair value. Our Level 1 assets include investments in publicly traded equity securities. These securities are actively traded and valued using quoted prices for identical securities from the market exchanges. Our Level 2 assets consist of fixed-income securities and commingled funds whose underlying investments are valued using observable marketplace inputs. The fair value of plan assets invested in fixed-income securities is generally determined under a market approach using valuation models that incorporate observable inputs such as interest rates, bond yields and quoted prices for similar assets. Our plan assets that are invested in commingled funds are valued using a unit price or net asset value (NAV) that is based on the underlying investments of the fund. Our Level 3 assets include real estate funds, insurance deposit contracts and direct private equity investments. Certain investments valued using NAV as a practical expedient are excluded from the fair value hierarchy. These investments are redeemable at NAV on a monthly or quarterly basis and have redemption notice periods of up to 90 days . Government Contract Considerations Our contractual arrangements with the U.S. government provide for the recovery of contributions to our pension and other post-retirement benefit plans covering employees working in our defense segments. For non-funded plans, our government contracts allow us to recover claims paid. Following payment, these recoverable amounts are allocated to contracts and billed to the customer in accordance with the Cost Accounting Standards (CAS) and specific contractual terms. For some of these plans, the cumulative pension and other post-retirement benefit cost exceeds the amount currently allocable to contracts. To the extent we consider recovery of the cost to be probable based on our backlog and probable follow-on contracts, we defer the excess in other contract costs in other current assets on the Consolidated Balance Sheet until the cost is allocable to contracts. See Note A for a discussion of our other contract costs. For other plans, the amount allocated to contracts and included in revenue has exceeded the plans’ cumulative benefit cost. We have similarly deferred recognition of these excess earnings on the Consolidated Balance Sheet. Defined-benefit Retirement Plan Summary Financial Information Estimating retirement plan assets, liabilities and costs requires the extensive use of actuarial assumptions. These include the long-term rate of return on plan assets, the interest rates used to discount projected benefit payments, healthcare cost trend rates and future salary increases. Given the long-term nature of the assumptions being made, actual outcomes can and often do differ from these estimates. Our annual benefit cost consists of three primary elements: the cost of benefits earned by employees for services rendered during the year, an interest charge on our plan liabilities and an assumed return on our plan assets for the year. The annual cost also includes gains and losses resulting from changes in actuarial assumptions, differences between the actual and assumed long-term rate of return on assets, and gains and losses resulting from changes we make to plan benefit terms. We recognize an asset or liability on the Consolidated Balance Sheet equal to the funded status of each of our defined-benefit retirement plans. The funded status is the difference between the fair value of the plan’s assets and its benefit obligation. Changes in plan assets and liabilities due to differences between actuarial assumptions and the actual results of the plan are deferred in AOCL rather than charged to earnings. These differences are then amortized over future years as a component of our annual benefit cost. We amortize actuarial differences under qualified plans on a straight-line basis over the average remaining service period of eligible employees. If all of a plan’s participants are inactive or are not accruing additional benefits, we amortize these differences over the average remaining life expectancy of the plan participants. We recognize the difference between the actual and expected return on plan assets for qualified plans over five years. The deferral of these differences reduces the volatility of our annual benefit cost that can result either from year-to-year changes in the assumptions or from actual results that are not necessarily representative of the long-term financial position of these plans. We recognize differences under nonqualified plans immediately. Pension Benefits. We have ten noncontributory and five contributory trusteed, qualified defined-benefit pension plans covering eligible government business employees, and two noncontributory and four contributory plans covering eligible commercial business employees, including some employees of our international operations. The primary factors affecting the benefits earned by participants in our pension plans are employees’ years of service and compensation levels. Our primary government pension plans, which comprise the majority of our unfunded obligation, were closed to new salaried participants on January 1, 2007. Additionally, we made changes to these plans for certain participants effective in 2014 that limit or cease the benefits that accrue for future service. We made similar changes to our primary commercial pension plan in 2015. We also sponsor one funded and several unfunded non-qualified supplemental executive retirement plans, which provide participants with additional benefits, including excess benefits over limits imposed on qualified plans by federal tax law. Other Post-retirement Benefits. We maintain plans that provide post-retirement healthcare and life insurance coverage for certain employees and retirees. These benefits vary by employment status, age, service and salary level at retirement. The coverage provided and the extent to which the retirees share in the cost of the program vary throughout the company. The plans provide health and life insurance benefits only to those employees who retire directly from our service and not to those who terminate service prior to eligibility for retirement. Contributions and Benefit Payments It is our policy to fund our defined-benefit retirement plans in a manner that optimizes the tax deductibility and contract recovery of contributions considered within our capital deployment framework. Therefore, we may make discretionary contributions in addition to the required contributions determined in accordance with IRS regulations. We maintain several tax-advantaged accounts, primarily Voluntary Employees’ Beneficiary Association (VEBA) trusts, to fund the obligations for some of our other post-retirement benefit plans. For non-funded plans, claims are paid as received.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of Net Interest Expense	Net interest expense consisted of the following: Year Ended December 31 2018 2017 2016 Interest expense $ 374 $ 117 $ 99 Interest income (18 ) (14 ) (8 ) Interest expense, net $ 356 $ 103 $ 91

Acquisitions and Divestitures_2

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations, Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Acquisition Consideration and Fair Value of Assets Acquired	The cash purchase price totaled $9.7 billion and consisted of the following: CSRA shares outstanding (in millions) 165.4 Cash consideration per CSRA share $ 41.25 Cash paid to purchase outstanding CSRA shares $ 6,825 Cash paid to extinguish CSRA debt 2,846 Cash settlement of outstanding CSRA stock options and restricted stock units 78 Total purchase price $ 9,749
Schedule of Estimated Fair Value of Assets Acquired and Liabilities Assumed on Acquisition Date	The following table summarizes the preliminary allocation of the purchase price to the estimated fair values of the assets acquired and liabilities assumed on the acquisition date, with the excess recorded as goodwill: Cash and equivalents $ 45 Accounts receivable 154 Unbilled receivables 510 Other current assets 301 Property, plant and equipment, net 673 Intangible assets, net 2,066 Goodwill 7,859 Other noncurrent assets 20 Total assets $ 11,628 Accounts payable $ (139 ) Customer advances and deposits (151 ) Current capital lease obligation (51 ) Other current liabilities (404 ) Noncurrent capital lease obligation (207 ) Noncurrent deferred tax liability (376 ) Other noncurrent liabilities (551 ) Total liabilities $ (1,879 ) Net assets acquired $ 9,749
Schedule of Pro Forma Information	The following pro forma information presents our consolidated revenue and earnings from continuing operations as if the acquisition of CSRA and the related financing transactions had occurred on January 1, 2017 : Year Ended December 31 2018 2017 Revenue $ 37,534 $ 35,828 Earnings from continuing operations 3,390 2,982 Diluted earnings per share from continuing operations $ 11.33 $ 9.79
Schedule of Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill by reporting unit were as follows: Aerospace Combat Systems Information Systems and Technology Information Technology Mission Systems Marine Systems Total Goodwill December 31, 2016 (a) $ 2,537 $ 2,598 $ 6,013 $ — $ — $ 297 $ 11,445 Acquisitions/ divestitures (b) 28 — 268 — — — 296 Other (c) 73 79 21 — — — 173 December 31, 2017 (a) 2,638 2,677 6,302 — — 297 11,914 Acquisitions/ divestitures (b) — — 16 — — — 16 Other (c) 40 (14 ) (1 ) — — — 25 April 1, 2018 (a) 2,678 2,663 6,317 — — 297 11,955 Change in reporting unit composition (d) — — (6,317 ) 2,076 4,241 — — Acquisitions/ divestitures (b) 183 30 — 7,601 7 — 7,821 Other (c) (48 ) (60 ) — (55 ) (19 ) — (182 ) December 31, 2018 (e) $ 2,813 $ 2,633 $ — $ 9,622 $ 4,229 $ 297 $ 19,594 (a) Goodwill in the Information Systems and Technology reporting unit is net of $1.9 billion of accumulated impairment losses. (b) Includes adjustments during the purchase price allocation period. Activity in the first quarter of 2018 and the nine-month period ended December 31, 2018 , also includes an allocation of goodwill associated with the sale of the commercial health products business and an allocation of goodwill associated with the sale of a public-facing contact-center business, respectively, as discussed above. (c) Consists primarily of adjustments for foreign currency translation. Activity in the nine-month period ended December 31, 2018 , also includes an allocation of goodwill in our Information Technology reporting unit associated with certain operations classified as held for sale on the Consolidated Balance Sheet on December 31, 2018 . (d) Concurrent with the acquisition of CSRA, we reorganized our Information Systems and Technology operating segment into the Information Technology and Mission Systems segments. See Note A for further discussion of the segment reorganization. This reorganization similarly changed the composition of our reporting units. Accordingly, goodwill of the Information Systems and Technology reporting unit was reassigned to the Information Technology and Mission Systems reporting units using a relative fair value allocation approach as of the date of the reorganization. (e) Goodwill in the Information Technology and Mission Systems reporting units is net of $536 and $1.3 billion of accumulated impairment losses, respectively.
Schedule of Intangible Assets	Intangible assets consisted of the following: Gross Carrying Amount (a) Accumulated Amortization Net Carrying Amount Gross Carrying Amount (a) Accumulated Amortization Net Carrying Amount December 31 2018 2017 Contract and program intangible assets (b) $ 3,771 $ (1,531 ) $ 2,240 $ 1,684 $ (1,320 ) $ 364 Trade names and trademarks 469 (177 ) 292 465 (160 ) 305 Technology and software 165 (116 ) 49 137 (105 ) 32 Other intangible assets 159 (155 ) 4 155 (154 ) 1 Total intangible assets $ 4,564 $ (1,979 ) $ 2,585 $ 2,441 $ (1,739 ) $ 702 (a) Change in gross carrying amounts consists primarily of adjustments for acquired intangible assets and foreign currency translation. (b) Consists of acquired backlog and probable follow-on work and associated customer relationships.
Schedule of Amortization Lives (In Years) of Intangible Assets	The amortization lives (in years) of our intangible assets on December 31, 2018 , were as follows: Intangible Asset Range of Amortization Life Contract and program intangible assets 7-30 Trade names and trademarks 30 Technology and software 5-20 Other intangible assets 2-7
Schedule of Expected Annual Amortization Expense Over the Next Five Years of Intangible Assets	We expect to record annual amortization expense over the next five years as follows: Year Ended December 31 Amortization Expense 2019 $ 280 2020 265 2021 217 2022 192 2023 175

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue Recognition [Abstract]
Schedule of Impact of Adjustments in Contract Estimates	The aggregate impact of adjustments in contract estimates increased our revenue, operating earnings and diluted earnings per share as follows: Year Ended December 31 2018 2017 2016 Revenue $ 377 $ 292 $ 95 Operating earnings 345 323 16 Diluted earnings per share $ 0.91 $ 0.69 $ 0.03
Schedule of Revenue by Major Products and Services	Revenue by major products and services was as follows: Year Ended December 31 2018 2017 2016 Aircraft manufacturing and completions $ 6,226 $ 6,320 $ 6,074 Aircraft services 2,096 1,743 1,625 Pre-owned aircraft 133 66 116 Total Aerospace 8,455 8,129 7,815 Military vehicles 4,027 3,731 3,378 Weapons systems, armament and munitions 1,798 1,633 1,517 Engineering and other services 416 585 635 Total Combat Systems 6,241 5,949 5,530 IT services 8,269 4,410 4,428 Total Information Technology 8,269 4,410 4,428 C4ISR solutions 4,726 4,481 4,716 Total Mission Systems 4,726 4,481 4,716 Nuclear-powered submarines 5,712 5,175 5,264 Surface ships 1,872 1,607 1,648 Repair and other services 918 1,222 1,160 Total Marine Systems 8,502 8,004 8,072 Total revenue $ 36,193 $ 30,973 $ 30,561
Schedule of Revenue by Contract Type	Revenue by contract type was as follows: Year Ended December 31, 2018 Aerospace Combat Systems Information Technology Mission Systems Marine Systems Total Fixed-price $ 7,600 $ 5,406 $ 3,396 $ 2,711 $ 5,493 $ 24,606 Cost-reimbursement — 800 3,422 1,861 3,004 9,087 Time-and-materials 855 35 1,451 154 5 2,500 Total revenue $ 8,455 $ 6,241 $ 8,269 $ 4,726 $ 8,502 $ 36,193 Year Ended December 31, 2017 Fixed-price $ 7,479 $ 5,090 $ 1,465 $ 2,478 $ 4,808 $ 21,320 Cost-reimbursement — 823 2,305 1,838 3,186 8,152 Time-and-materials 650 36 640 165 10 1,501 Total revenue $ 8,129 $ 5,949 $ 4,410 $ 4,481 $ 8,004 $ 30,973 Year Ended December 31, 2016 Fixed-price $ 7,208 $ 4,629 $ 1,514 $ 2,737 $ 4,857 $ 20,945 Cost-reimbursement — 865 2,262 1,822 3,204 8,153 Time-and-materials 607 36 652 157 11 1,463 Total revenue $ 7,815 $ 5,530 $ 4,428 $ 4,716 $ 8,072 $ 30,561
Schedule of Revenue by Customer	Revenue by customer was as follows: Year Ended December 31, 2018 Aerospace Combat Systems Information Technology Mission Systems Marine Systems Total U.S. government: Department of Defense (DoD) $ 236 $ 2,903 $ 3,291 $ 3,224 $ 8,098 $ 17,752 Non-DoD — 8 4,712 506 2 5,228 Foreign Military Sales (FMS) 98 317 22 44 145 626 Total U.S. government 334 3,228 8,025 3,774 8,245 23,606 U.S. commercial 4,175 251 163 138 245 4,972 Non-U.S. government 551 2,698 81 662 10 4,002 Non-U.S. commercial 3,395 64 — 152 2 3,613 Total revenue $ 8,455 $ 6,241 $ 8,269 $ 4,726 $ 8,502 $ 36,193 Year Ended December 31, 2017 U.S. government: DoD $ 189 $ 2,702 $ 1,802 $ 3,027 $ 7,721 $ 15,441 Non-DoD — 8 2,340 556 — 2,904 FMS 42 374 22 46 192 676 Total U.S. government 231 3,084 4,164 3,629 7,913 19,021 U.S. commercial 3,885 220 214 108 71 4,498 Non-U.S. government 210 2,580 32 607 13 3,442 Non-U.S. commercial 3,803 65 — 137 7 4,012 Total revenue $ 8,129 $ 5,949 $ 4,410 $ 4,481 $ 8,004 $ 30,973 Year Ended December 31, 2016 U.S. government: DoD $ 231 $ 2,274 $ 1,781 $ 3,287 $ 7,507 $ 15,080 Non-DoD — 7 2,343 525 8 2,883 FMS 130 333 23 25 202 713 Total U.S. government 361 2,614 4,147 3,837 7,717 18,676 U.S. commercial 3,501 287 259 108 329 4,484 Non-U.S. government 496 2,520 8 613 26 3,663 Non-U.S. commercial 3,457 109 14 158 — 3,738 Total revenue $ 7,815 $ 5,530 $ 4,428 $ 4,716 $ 8,072 $ 30,561

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Weighted Average Shares Outstanding	Basic and diluted weighted average shares outstanding were as follows (in thousands): Year Ended December 31 2018 2017 2016 Basic weighted average shares outstanding 295,262 299,172 304,707 Dilutive effect of stock options and restricted stock/RSUs* 3,898 5,465 5,680 Diluted weighted average shares outstanding 299,160 304,637 310,387 * Excludes outstanding options to purchase shares of common stock that had exercise prices in excess of the average market price of our common stock during the year and, therefore, the effect of including these options would be antidilutive. These options totaled 3,143 in 2018 , 1,547 in 2017 and 4,201 in 2016 .

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Carrying And Fair Values Of Other Financial Assets And Liabilities	The following tables present the fair values of our other financial assets and liabilities on December 31, 2018 and 2017 , and the basis for determining their fair values: Carrying Value Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets (Liabilities) December 31, 2018 Measured at fair value: Marketable securities held in trust: Cash and equivalents $ 29 $ 29 $ 23 $ 6 $ — Available-for-sale debt securities 121 121 — 121 — Equity securities 52 52 52 — — Other investments 4 4 — — 4 Cash flow hedges (69 ) (69 ) — (69 ) — Measured at amortized cost: Short- and long-term debt principal (12,518 ) (12,346 ) — (12,346 ) — December 31, 2017 Measured at fair value: Marketable securities held in trust: Cash and equivalents $ 20 $ 20 $ 15 $ 5 $ — Available-for-sale debt securities 117 117 — 117 — Equity securities 54 54 54 — — Other investments 4 4 — — 4 Cash flow hedges (105 ) (105 ) — (105 ) — Measured at amortized cost: Short- and long-term debt principal (4,032 ) (3,974 ) — (3,974 ) —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Net Provision For Income Taxes For Continuing Operations	The following is a summary of our net provision for income taxes for continuing operations: Year Ended December 31 2018 2017 2016 Current: U.S. federal $ 587 $ 656 $ 698 State 48 31 24 International 95 77 71 Total current 730 764 793 Deferred: U.S. federal (37 ) 215 140 State 8 7 7 International 26 60 37 Adjustment for enacted change in U.S. tax law — 119 — Total deferred (3 ) 401 184 Provision for income taxes, net $ 727 $ 1,165 $ 977 Net income tax payments $ 532 $ 617 $ 959
Schedule of Reconciliation From Statutory Federal Income Tax Rate To Effective Income Tax Rate	The reconciliation from the statutory federal income tax rate to our effective income tax rate follows: Year Ended December 31 2018 2017 2016 Statutory federal income tax rate 21.0 % 35.0 % 35.0 % State tax on commercial operations, net of federal benefits 1.1 0.6 0.6 Impact of international operations 0.6 (4.5 ) (4.0 ) Domestic production deduction — (1.5 ) (1.5 ) Foreign derived intangible income (1.2 ) — — Equity-based compensation (1.1 ) (2.6 ) (2.3 ) Domestic tax credits (1.1 ) (0.8 ) (0.9 ) Contract close-outs (0.5 ) — — Adoption impact of enacted change in U.S. tax law — 2.9 — Other, net (1.0 ) (0.5 ) (0.2 ) Effective income tax rate 17.8 % 28.6 % 26.7 %
Schedule of Tax Effects Of Temporary Differences Between Reported Earnings And Taxable Earnings	The tax effects of temporary differences between reported earnings and taxable income consisted of the following: December 31 2018 2017 Retirement benefits $ 1,055 $ 935 Tax loss and credit carryforwards 393 437 Salaries and wages 160 137 Workers’ compensation 138 139 Other 351 335 Deferred assets 2,097 1,983 Valuation allowances (336 ) (402 ) Net deferred assets $ 1,761 $ 1,581 Intangible assets $ (1,061 ) $ (688 ) Contract accounting methods (530 ) (500 ) Property, plant and equipment (265 ) (182 ) Capital Construction Fund qualified ships (160 ) (159 ) Other (284 ) (221 ) Deferred liabilities $ (2,300 ) $ (1,750 ) Net deferred tax liability $ (539 ) $ (169 )
Schedule of Net Deferred Tax Asset (Liability)	Our net deferred tax liability consisted of the following: December 31 2018 2017 Deferred tax asset $ 38 $ 75 Deferred tax liability (577 ) (244 ) Net deferred tax liability $ (539 ) $ (169 )

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2018
Accounts Receivable, Net [Abstract]
Schedule of Accounts Receivable	Accounts receivable consisted of the following: December 31 2018 2017 Non-U.S. government $ 2,035 $ 2,228 U.S. government 1,189 971 Commercial 535 418 Total accounts receivable $ 3,759 $ 3,617

Unbilled Receivables (Tables)

Unbilled Receivables (Tables)	12 Months Ended
	Dec. 31, 2018
Contractors [Abstract]
Schedule of Unbilled Receivables	Unbilled receivables consisted of the following: December 31 2018 2017 Unbilled revenue $ 27,908 $ 21,845 Advances and progress billings (21,332 ) (16,605 ) Net unbilled receivables $ 6,576 $ 5,240

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following: December 31 2018 2017 Work in process $ 4,357 $ 3,872 Raw materials 1,504 1,357 Finished goods 33 51 Pre-owned aircraft 83 23 Total inventories $ 5,977 $ 5,303

Property, Plant And Equipment_2

Property, Plant And Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant And Equipment, Net	PP&E by major asset class consisted of the following: December 31 2018 2017 Machinery and equipment $ 5,534 $ 4,736 Buildings and improvements 3,011 2,837 Land and improvements 386 357 Construction in process 472 307 Total PP&E 9,403 8,237 Accumulated depreciation (5,055 ) (4,720 ) PP&E, net $ 4,348 $ 3,517

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Debt	Debt consisted of the following: December 31 2018 2017 Fixed-rate notes due: Interest rate: May 2020 2.875% $ 2,000 $ — May 2021 3.000% 2,000 — July 2021 3.875% 500 500 November 2022 2.250% 1,000 1,000 May 2023 3.375% 750 — August 2023 1.875% 500 500 November 2024 2.375% 500 500 May 2025 3.500% 750 — August 2026 2.125% 500 500 November 2027 2.625% 500 500 May 2028 3.750% 1,000 — November 2042 3.600% 500 500 Floating-rate notes due: May 2020 3-month LIBOR + 0.29% 500 — May 2021 3-month LIBOR + 0.38% 500 — Commercial paper 2.568% 850 — Other Various 168 32 Total debt principal 12,518 4,032 Less unamortized debt issuance costs and discounts 101 50 Total debt 12,417 3,982 Less current portion 973 2 Long-term debt $ 11,444 $ 3,980
Schedule of Principal Maturities of Debt	The aggregate amounts of scheduled principal maturities of our debt are as follows: Year Ended December 31 Debt Principal 2019 $ 973 2020 2,501 2021 3,002 2022 1,002 2023 1,252 Thereafter 3,788 Total debt principal $ 12,518

Other Liabilities (Tables)

Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Schedule of Significant Other Liabilities By Balance Sheet Caption	A summary of significant other liabilities by balance sheet caption follows: December 31 2018 2017 Salaries and wages $ 952 $ 786 Retirement benefits 272 295 Workers’ compensation 244 320 Fair value of cash flow hedges 141 180 Other (a) 1,708 1,317 Total other current liabilities $ 3,317 $ 2,898 Retirement benefits $ 4,422 $ 4,408 Customer deposits on commercial contracts 726 814 Deferred income taxes 577 244 Other (b) 1,768 1,066 Total other liabilities $ 7,493 $ 6,532 (a) Consists primarily of dividends payable, taxes payable, capital lease obligations, environmental remediation reserves, warranty reserves, deferred revenue and supplier contributions in the Aerospace segment, liabilities of discontinued operations, and insurance-related costs. (b) Consists primarily of capital lease obligations, warranty reserves, workers’ compensation liabilities and liabilities of discontinued operations.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Schedule of Accumulated Other Comprehensive Income	The changes, pretax and net of tax, in each component of AOCL consisted of the following: Losses on Cash Flow Hedges Unrealized Gains on Marketable Securities Foreign Currency Translation Adjustments Changes in Retirement Plans’ Funded Status AOCL December 31, 2015 $ (487 ) $ 20 $ 181 $ (2,997 ) $ (3,283 ) Other comprehensive loss, pretax 191 (9 ) (112 ) (192 ) (122 ) Benefit from income tax, net (49 ) 3 — 64 18 Other comprehensive loss, net of tax 142 (6 ) (112 ) (128 ) (104 ) December 31, 2016 (345 ) 14 69 (3,125 ) (3,387 ) Other comprehensive income, pretax 341 9 348 20 718 Provision for income tax, net (90 ) (4 ) (15 ) (42 ) (151 ) Other comprehensive income, net of tax 251 5 333 (22 ) 567 December 31, 2017 (94 ) 19 402 (3,147 ) (2,820 ) Cumulative effect adjustments (see Note A) (4 ) (19 ) — (615 ) (638 ) Other comprehensive loss, pretax 36 — (300 ) (61 ) (325 ) Benefit from income tax, net (9 ) — — 14 5 Other comprehensive loss, net of tax 27 — (300 ) (47 ) (320 ) December 31, 2018 $ (71 ) $ — $ 102 $ (3,809 ) $ (3,778 )

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments are as follows: Year Ended December 31 Future Minimum Lease Payments 2019 $ 297 2020 234 2021 196 2022 154 2023 110 Thereafter 698 Total future minimum lease payments $ 1,689
Schedule of Changes In Carrying Amount Of Warranty Liabilities	The changes in the carrying amount of warranty liabilities for each of the past three years were as follows: Year Ended December 31 2018 2017 2016 Beginning balance $ 467 $ 474 $ 434 Warranty expense 129 146 155 Payments (102 ) (123 ) (100 ) Adjustments (14 ) (30 ) (15 ) Ending balance $ 480 $ 467 $ 474
Schedule of Future Minimum Lease Payments for Capital Leases	The future minimum lease payments are as follows: Year Ended December 31 Future Minimum Lease Payments 2019 $ 92 2020 84 2021 78 2022 79 2023 30 Thereafter 70 Total future minimum lease payments 433 Less amount representing interest 95 Less amount representing executory costs 19 Present value of net minimum lease payments 319 Less current maturities of capital lease liability 64 Non-current capital lease liability $ 255

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Equity-Based Compensation Expense	The following table details the components of equity-based compensation expense recognized in net earnings in each of the past three years: Year Ended December 31 2018 2017 2016 Stock options $ 45 $ 34 $ 25 Restricted stock/RSUs 65 46 36 Total equity-based compensation expense, net of tax $ 110 $ 80 $ 61
Schedule of Assumptions Of Fair Value Options On The Date Of Grant Using Black-Scholes Option Pricing Model	We estimate the fair value of stock options on the date of grant using the Black-Scholes option pricing model with the following assumptions for each of the past three years: Year Ended December 31 2018 2017 2016 Expected volatility 17.6-18.2% 17.3-19.4% 19.1-20.0% Weighted average expected volatility 17.6% 19.4% 20.0% Expected term (in months) 68 68 70 Risk-free interest rate 2.6-2.9% 2.0-2.2% 1.5-1.6% Expected dividend yield 1.8% 1.8% 2.0%
Schedule of Stock Option Activity	A summary of stock option activity during 2018 follows: In Shares and Dollars Shares Under Option Weighted Average Exercise Price Per Share Outstanding on December 31, 2017 10,620,389 $ 126.08 Granted 1,730,430 223.06 Exercised (1,388,110 ) 104.48 Forfeited/canceled (197,514 ) 182.08 Outstanding on December 31, 2018 10,765,195 $ 143.43 Vested and expected to vest on December 31, 2018 10,595,953 $ 142.32 Exercisable on December 31, 2018 6,119,560 $ 109.19
Schedule of Stock Options' Intrinsic Value And Remaining Contractual Term	Summary information with respect to our stock options’ intrinsic value and remaining contractual term on December 31, 2018 , follows: Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Outstanding 5.5 $ 320 Vested and expected to vest 5.4 319 Exercisable 3.4 294
Schedule of Restricted Stock And Restricted Stock Unit Activity	A summary of restricted stock and RSU activity during 2018 follows: In Shares and Dollars Shares/ Share-Equivalent Units Weighted Average Grant-Date Fair Value Per Share Nonvested at December 31, 2017 1,983,173 $ 135.38 Granted 482,700 204.97 Vested (1,163,702 ) 122.59 Forfeited (39,895 ) 195.99 Nonvested at December 31, 2018 1,262,276 $ 171.62

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Schedule of Benefits To Be Paid From Retirement Plans Over The Next Ten Years	We expect the following benefits to be paid from our retirement plans over the next 10 years: Pension Benefits Other Post-retirement 2019 $ 816 $ 68 2020 846 67 2021 873 66 2022 899 65 2023 927 64 2024-2028 4,947 296
Schedule of Annual Pension and Other Post-retirement Benefit Costs	Net annual defined-benefit pension and other post-retirement benefit cost (credit) consisted of the following: Pension Benefits Year Ended December 31 2018 2017 2016 Service cost $ 180 $ 168 $ 173 Interest cost 532 453 456 Expected return on plan assets (856 ) (679 ) (713 ) Recognized net actuarial loss 359 362 343 Amortization of prior service credit (46 ) (66 ) (68 ) Net annual benefit cost $ 169 $ 238 $ 191 Other Post-retirement Benefits Year Ended December 31 2018 2017 2016 Service cost $ 10 $ 9 $ 10 Interest cost 33 30 34 Expected return on plan assets (40 ) (34 ) (33 ) Recognized net actuarial gain (4 ) (4 ) (3 ) Amortization of prior service credit (4 ) (3 ) (6 ) Net annual benefit (credit) cost $ (5 ) $ (2 ) $ 2
Schedule of Reconciliation of Benefit Obligations And Plan or Trust Assets And Resulting Funded Status Of Defined Benefit Retirement Plans	The following is a reconciliation of the benefit obligations and plan/trust assets, and the resulting funded status, of our defined-benefit retirement plans: Pension Benefits Other Post-retirement Benefits Year Ended December 31 2018 2017 2018 2017 Change in Benefit Obligation Benefit obligation at beginning of year $ (14,212 ) $ (13,022 ) $ (996 ) $ (1,005 ) Service cost (180 ) (168 ) (10 ) (9 ) Interest cost (532 ) (453 ) (33 ) (30 ) Acquisitions (2,758 ) — (62 ) — Amendments 15 1 — — Actuarial gain (loss) 1,183 (1,098 ) 78 (42 ) Settlement/curtailment/other 23 (58 ) 21 27 Benefits paid 741 586 67 63 Benefit obligation at end of year $ (15,720 ) $ (14,212 ) $ (935 ) $ (996 ) Change in Plan/Trust Assets Fair value of assets at beginning of year $ 10,130 $ 8,980 $ 541 $ 499 Actual return on plan assets (749 ) 1,469 (4 ) 82 Acquisitions 2,328 — 77 — Employer contributions 571 199 1 3 Settlement/curtailment/other (26 ) 56 — — Benefits paid (722 ) (574 ) (45 ) (43 ) Fair value of assets at end of year $ 11,532 $ 10,130 $ 570 $ 541 Funded status at end of year $ (4,188 ) $ (4,082 ) $ (365 ) $ (455 )
Schedule of Amounts Recognized On Consolidated Balance Sheet	Amounts recognized on the Consolidated Balance Sheet consisted of the following: Pension Benefits Other Post-retirement Benefits December 31 2018 2017 2018 2017 Noncurrent assets $ 67 $ 133 $ 74 $ 33 Current liabilities (131 ) (145 ) (141 ) (150 ) Noncurrent liabilities (4,124 ) (4,070 ) (298 ) (338 ) Net liability recognized $ (4,188 ) $ (4,082 ) $ (365 ) $ (455 )
Schedule of Amounts Deferred In AOCI	Amounts deferred in AOCL consisted of the following: Pension Benefits Other Post-retirement Benefits December 31 2018 2017 2018 2017 Net actuarial loss (gain) $ 4,959 $ 4,899 $ (37 ) $ (5 ) Prior service (credit) cost (95 ) (124 ) 1 (3 ) Total amount recognized in AOCL, pretax $ 4,864 $ 4,775 $ (36 ) $ (8 ) The following is a reconciliation of the change in AOCL for our defined-benefit retirement plans: Pension Benefits Other Post-retirement Benefits Year Ended December 31 2018 2017 2018 2017 Net actuarial loss (gain) $ 422 $ 308 $ (34 ) $ (6 ) Prior service cost (15 ) (1 ) — — Amortization of: Net actuarial (loss) gain from prior years (359 ) (362 ) 4 4 Prior service credit 46 66 4 3 Other* (5 ) 7 (2 ) (39 ) Change in AOCL, pretax $ 89 $ 18 $ (28 ) $ (38 ) * Includes foreign exchange translation, curtailment and other adjustments.
Schedule of Amounts Deferred In AOCI On The Consolidated Balance Sheet	The following table represents amounts deferred in AOCL on the Consolidated Balance Sheet on December 31, 2018 , that we expect to recognize in our retirement benefit cost in 2019 : Pension Other Post-retirement Net actuarial loss (gain) $ 280 $ (8 ) Prior service credit (18 ) (4 )
Schedule of ABO That Exceeded The Plans' Assets	On December 31, 2018 and 2017 , some of our pension plans had an ABO that exceeded the plans’ assets. Summary information for those plans follows: December 31 2018 2017 PBO $ (15,067 ) $ (13,660 ) ABO (14,856 ) (13,398 ) Fair value of plan assets 10,832 9,526
Schedule of Assumptions Used To Determine Benefit Obligations And Benefit Costs	The following table summarizes the weighted average assumptions used to determine our net annual benefit cost: Assumptions for Year Ended December 31 2018 2017 2016 Pension Benefits Discount rates: Benefit obligation 3.69 % 4.19 % 4.46 % Service cost 3.51 % 4.13 % 4.42 % Interest cost 3.34 % 3.56 % 3.71 % Expected long-term rate of return on assets 7.45 % 7.43 % 8.14 % Rate of increase in compensation levels 2.79 % 2.90 % 3.39 % Other Post-retirement Benefits Discount rates: Benefit obligation 3.64 % 4.11 % 4.35 % Service cost 3.79 % 4.34 % 4.52 % Interest cost 3.27 % 3.43 % 3.53 % Expected long-term rate of return on assets 7.75 % 7.76 % 7.81 % The following table summarizes the weighted average assumptions used to determine our benefit obligations: Assumptions on December 31 2018 2017 Pension Benefits Benefit obligation discount rate 4.28 % 3.62 % Rate of increase in compensation levels 2.79 % 2.82 % Other Post-retirement Benefits Benefit obligation discount rate 4.24 % 3.64 % Healthcare cost trend rate: Trend rate for next year 6.50 % 6.50 % Ultimate trend rate 5.00 % 5.00 % Year rate reaches ultimate trend rate 2024 2024
Schedule of Defined Benefit Plan, Effect of Point Twenty Five Percentage Point Change on Net Cost	For our U.S. pension plans that represent the majority of our total obligation, the following hypothetical changes in the discount rates and expected long-term rates of return on plan assets would have had the following impact in 2018 : Increase 25 Basis Points Decrease 25 Basis Points Increase (decrease) to net pension cost from: Change in discount rates $ (24 ) $ 25 Change in long-term rates of return on plan assets (27 ) 27
Schedule of Asset Allocation Policy Ranges	At the end of 2018 , our asset allocation policy ranges were: Equities 48-68% Fixed income 20-48% Cash 0-5% Other asset classes 0-16%
Schedule of Fair Value of Plan Assets By Investment Category And The Corresponding Level Within The Fair Value Hierarchy	The fair value of our other post-retirement benefit plan assets by category and the corresponding level within the fair value hierarchy were as follows: Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Asset Category (a) December 31, 2018 Cash and equivalents $ 23 $ — $ 23 Equity securities 80 80 — Fixed-income securities 87 — 87 Commingled funds: Equity funds 237 — 237 Fixed-income funds 111 — 111 Real estate funds 2 2 — Total plan assets in fair value hierarchy $ 540 $ 82 $ 458 Plan assets measured using NAV as a practical expedient (b): Hedge funds 22 Equity funds 3 Fixed-income funds 3 Real estate funds 2 Total other post-retirement benefit plan assets $ 570 (a) We had no Level 3 investments on December 31, 2018 . (b) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Asset Category (a) December 31, 2017 Cash and equivalents $ 18 $ — $ 18 Equity securities 70 70 — Fixed-income securities 89 — 89 Commingled funds: Equity funds 260 — 260 Fixed-income funds 99 — 99 Real estate funds 2 2 — Total plan assets in fair value hierarchy $ 538 $ 72 $ 466 Plan assets measured using NAV as a practical expedient (b): Real estate funds 2 Hedge funds 1 Total other post-retirement benefit plan assets $ 541 (a) We had no Level 3 investments on December 31, 2017 . (b) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. The fair value of our pension plan assets by investment category and the corresponding level within the fair value hierarchy were as follows: Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Asset Category December 31, 2018 Cash and equivalents $ 73 $ — $ 73 $ — Equity securities (a): U.S. companies 732 732 — — Non-U.S. companies 117 117 — — Private equity investments 20 — — 20 Fixed-income securities: Corporate bonds (b) 1,600 — 1,600 — Treasury securities 1,410 — 1,410 — Commingled funds: Equity funds 5,243 — 5,243 — Fixed-income funds 624 — 624 — Real estate funds 68 — — 68 Other investments: Insurance deposit contracts 128 — — 128 Total plan assets in fair value hierarchy $ 10,015 $ 849 $ 8,950 $ 216 Plan assets measured using NAV as a practical expedient (c): Hedge funds 910 Real estate funds 420 Fixed-income funds 101 Equity funds 86 Total pension plan assets $ 11,532 (a) No single equity holding amounted to more than 1% of the total fair value. (b) Our corporate bond investments had an average rating of A+ . (c) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets. Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Asset Category December 31, 2017 Cash and equivalents $ 48 $ — $ 48 $ — Equity securities (a): U.S. companies 770 770 — — Non-U.S. companies 97 97 — — Private equity investments 18 — — 18 Fixed-income securities: Corporate bonds (b) 1,604 — 1,604 — Treasury securities 1,361 — 1,361 — Commingled funds: Equity funds 5,018 — 5,018 — Fixed-income funds 325 — 325 — Real estate funds 51 — — 51 Other investments: Insurance deposit contracts 120 — — 120 Total plan assets in fair value hierarchy $ 9,412 $ 867 $ 8,356 $ 189 Plan assets measured using NAV as a practical expedient (c): Real estate funds 390 Hedge funds 328 Total pension plan assets $ 10,130 (a) No single equity holding amounted to more than 1% of the total fair value. (b) Our corporate bond investments had an average rating of A+ . (c) Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets.
Schedule of Changes In Level 3 Retirement Plan Assets	Changes in our Level 3 retirement plan assets during 2018 and 2017 were as follows: Private Equity Investments Real Estate Funds Insurance Deposits Contracts Total Level 3 Assets December 31, 2016 $ 13 $ 42 $ 109 $ 164 Actual return on plan assets: Unrealized gains, net 1 4 4 9 Realized gains, net — — 2 2 Purchases, sales and settlements, net 4 5 5 14 December 31, 2017 18 51 120 189 Actual return on plan assets: Unrealized losses, net — (1 ) — (1 ) Realized gains, net — — 3 3 Purchases, sales and settlements, net 2 18 5 25 December 31, 2018 $ 20 $ 68 $ 128 $ 216

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Schedule of Financial Information For Each Of Our Business Groups	The following is additional summary financial information for each of our segments: Identifiable Assets Capital Expenditures Depreciation and Amortization Year Ended December 31 2018 2017 2016 2018 2017 2016 2018 2017 2016 Aerospace $ 11,220 $ 10,126 $ 9,792 $ 194 $ 132 $ 125 $ 154 $ 147 $ 153 Combat Systems 9,853 9,846 8,885 91 84 71 87 86 86 Information Technology 14,159 3,021 2,778 62 16 10 333 32 42 Mission Systems 5,984 5,856 5,667 49 47 87 65 60 61 Marine Systems 3,130 2,906 3,063 243 123 92 116 109 105 Corporate* 1,062 3,291 2,987 51 26 7 8 7 6 Total $ 45,408 $ 35,046 $ 33,172 $ 690 $ 428 $ 392 $ 763 $ 441 $ 453 * Corporate identifiable assets are primarily cash and equivalents. Summary financial information for each of our segments follows: Revenue Operating Earnings Revenue from U.S. Government Year Ended December 31 2018 2017 2016 2018 2017 2016 2018 2017 2016 Aerospace $ 8,455 $ 8,129 $ 7,815 $ 1,490 $ 1,577 $ 1,394 $ 334 $ 231 $ 361 Combat Systems 6,241 5,949 5,530 962 937 831 3,228 3,084 2,614 Information Technology 8,269 4,410 4,428 608 373 340 8,025 4,164 4,147 Mission Systems 4,726 4,481 4,716 659 638 601 3,774 3,629 3,837 Marine Systems 8,502 8,004 8,072 761 685 595 8,245 7,913 7,717 Corporate — — — (23 ) 26 (17 ) — — — Total $ 36,193 $ 30,973 $ 30,561 $ 4,457 $ 4,236 $ 3,744 $ 23,606 $ 19,021 $ 18,676
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	The following table presents our revenue by geographic area based on the location of our customers: Year Ended December 31 2018 2017 2016 North America: United States $ 28,578 $ 23,519 $ 23,160 Other 755 915 709 Total North America 29,333 24,434 23,869 Europe 2,772 2,558 2,152 Asia/Pacific 2,252 2,011 1,650 Africa/Middle East 1,565 1,655 2,617 South America 271 315 273 Total revenue $ 36,193 $ 30,973 $ 30,561

Condensed Consolidating Finan_2

Condensed Consolidating Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2018
Consolidating Financial Statements [Abstract]
Condensed Consolidating Statements of Earnings	CONDENSED CONSOLIDATING STATEMENT OF EARNINGS Year Ended December 31, 2018 Parent Guarantors on a Combined Basis Other Subsidiaries Consolidating Adjustments Total Consolidated Revenue $ — $ 28,132 $ 8,061 $ — $ 36,193 Cost of sales 67 (22,841 ) (6,704 ) — (29,478 ) G&A (90 ) (1,638 ) (530 ) — (2,258 ) Operating earnings (23 ) 3,653 827 — 4,457 Interest, net (326 ) — (30 ) — (356 ) Other, net (81 ) 12 53 — (16 ) Earnings before income tax (430 ) 3,665 850 — 4,085 Provision for income tax, net 116 (677 ) (166 ) — (727 ) Discontinued operations, net of tax (13 ) — — — (13 ) Equity in net earnings of subsidiaries 3,672 — — (3,672 ) — Net earnings $ 3,345 $ 2,988 $ 684 $ (3,672 ) $ 3,345 Comprehensive income $ 3,025 $ 2,992 $ 305 $ (3,297 ) $ 3,025 Year Ended December 31, 2017 Revenue $ — $ 26,933 $ 4,040 $ — $ 30,973 Cost of sales 76 (21,695 ) (3,112 ) — (24,731 ) G&A (48 ) (1,643 ) (315 ) — (2,006 ) Operating earnings 28 3,595 613 — 4,236 Interest, net (97 ) 1 (7 ) — (103 ) Other, net (72 ) 12 4 — (56 ) Earnings before income tax (141 ) 3,608 610 — 4,077 Provision for income tax, net 154 (1,262 ) (57 ) — (1,165 ) Equity in net earnings of subsidiaries 2,899 — — (2,899 ) — Net earnings $ 2,912 $ 2,346 $ 553 $ (2,899 ) $ 2,912 Comprehensive income $ 3,479 $ 2,336 $ 1,158 $ (3,494 ) $ 3,479 Year Ended December 31, 2016 Revenue $ — $ 26,573 $ 3,988 $ — $ 30,561 Cost of sales 21 (21,811 ) (3,106 ) — (24,896 ) G&A (37 ) (1,568 ) (316 ) — (1,921 ) Operating earnings (16 ) 3,194 566 — 3,744 Interest, net (91 ) (2 ) 2 — (91 ) Other, net (11 ) 5 9 — 3 Earnings before income tax (118 ) 3,197 577 — 3,656 Provision for income tax, net 121 (1,055 ) (43 ) — (977 ) Discontinued operations, net of tax (107 ) — — — (107 ) Equity in net earnings of subsidiaries 2,676 — — (2,676 ) — Net earnings $ 2,572 $ 2,142 $ 534 $ (2,676 ) $ 2,572 Comprehensive income $ 2,468 $ 2,112 $ 543 $ (2,655 ) $ 2,468
Condensed Consolidating Balance Sheet	CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2018 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated ASSETS Current assets: Cash and equivalents $ 460 $ — $ 503 $ — $ 963 Accounts receivable — 1,171 2,588 — 3,759 Unbilled receivables — 2,758 3,818 — 6,576 Inventories — 5,855 122 — 5,977 Other current assets (45 ) 441 518 — 914 Total current assets 415 10,225 7,549 — 18,189 Noncurrent assets: PP&E 273 7,197 1,933 — 9,403 Accumulated depreciation of PP&E (83 ) (4,075 ) (897 ) — (5,055 ) Intangible assets, net — 251 2,334 — 2,585 Goodwill — 8,031 11,563 — 19,594 Other assets 195 258 239 — 692 Net investment in subsidiaries 25,313 — — (25,313 ) — Total noncurrent assets 25,698 11,662 15,172 (25,313 ) 27,219 Total assets $ 26,113 $ 21,887 $ 22,721 $ (25,313 ) $ 45,408 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities: Short-term debt and current portion of long-term debt $ 850 $ — $ 123 $ — $ 973 Customer advances and deposits — 4,541 2,729 — 7,270 Other current liabilities 552 3,944 2,000 — 6,496 Total current liabilities 1,402 8,485 4,852 — 14,739 Noncurrent liabilities: Long-term debt 11,398 39 7 — 11,444 Other liabilities 1,581 4,073 1,839 — 7,493 Total noncurrent liabilities 12,979 4,112 1,846 — 18,937 Total shareholders’ equity 11,732 9,290 16,023 (25,313 ) 11,732 Total liabilities and shareholders’ equity $ 26,113 $ 21,887 $ 22,721 $ (25,313 ) $ 45,408 CONDENSED CONSOLIDATING BALANCE SHEET December 31, 2017 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated ASSETS Current assets: Cash and equivalents $ 1,930 $ — $ 1,053 $ — $ 2,983 Accounts receivable — 1,259 2,358 — 3,617 Unbilled receivables — 2,547 2,693 — 5,240 Inventories — 5,216 87 — 5,303 Other current assets 351 461 373 — 1,185 Total current assets 2,281 9,483 6,564 — 18,328 Noncurrent assets: PP&E 221 6,779 1,237 — 8,237 Accumulated depreciation of PP&E (75 ) (3,869 ) (776 ) — (4,720 ) Intangible assets, net — 287 415 — 702 Goodwill — 8,320 3,594 — 11,914 Other assets 199 232 154 — 585 Net investment in subsidiaries 15,771 — — (15,771 ) — Total noncurrent assets 16,116 11,749 4,624 (15,771 ) 16,718 Total assets $ 18,397 $ 21,232 $ 11,188 $ (15,771 ) $ 35,046 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities: Short-term debt and current portion of long-term debt $ — $ 1 $ 1 $ — $ 2 Customer advances and deposits — 4,180 2,812 — 6,992 Other current liabilities 561 3,758 1,786 — 6,105 Total current liabilities 561 7,939 4,599 — 13,099 Noncurrent liabilities: Long-term debt 3,950 21 9 — 3,980 Other liabilities 2,451 3,473 608 — 6,532 Total noncurrent liabilities 6,401 3,494 617 — 10,512 Total shareholders’ equity 11,435 9,799 5,972 (15,771 ) 11,435 Total liabilities and shareholders’ equity $ 18,397 $ 21,232 $ 11,188 $ (15,771 ) $ 35,046
Condensed Consolidating Statements of Cash Flows	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2018 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated Net cash provided by operating activities* $ (579 ) $ 2,954 $ 773 $ — $ 3,148 Cash flows from investing activities: Business acquisitions, net of cash acquired (9,749 ) (74 ) (276 ) — (10,099 ) Capital expenditures (51 ) (513 ) (126 ) — (690 ) Proceeds from sales of assets 90 472 — — 562 Other, net 4 (12 ) 1 — (7 ) Net cash used by investing activities (9,706 ) (127 ) (401 ) — (10,234 ) Cash flows from financing activities: Proceeds from fixed-rate notes 6,461 — — — 6,461 Purchases of common stock (1,769 ) — — — (1,769 ) Dividends paid (1,075 ) — — — (1,075 ) Proceeds from floating-rate notes 1,000 — — — 1,000 Proceeds from commercial paper, net 851 — — — 851 Repayment of CSRA accounts receivable purchase agreement — — (450 ) — (450 ) Other, net 2 35 31 — 68 Net cash provided by financing activities 5,470 35 (419 ) — 5,086 Net cash used by discontinued operations (20 ) — — — (20 ) Cash sweep/funding by parent 3,365 (2,862 ) (503 ) — — Net decrease in cash and equivalents (1,470 ) — (550 ) — (2,020 ) Cash and equivalents at beginning of year 1,930 — 1,053 — 2,983 Cash and equivalents at end of year $ 460 $ — $ 503 $ — $ 963 Year Ended December 31, 2017 Net cash provided by operating activities* $ 312 $ 2,371 $ 1,193 $ — $ 3,876 Cash flows from investing activities: Capital expenditures (26 ) (330 ) (72 ) — (428 ) Business acquisitions, net of cash acquired — (350 ) (49 ) — (399 ) Other, net 10 31 (2 ) — 39 Net cash used by investing activities (16 ) (649 ) (123 ) — (788 ) Cash flows from financing activities: Purchases of common stock (1,558 ) — — — (1,558 ) Dividends paid (986 ) — — — (986 ) Proceeds from fixed-rate notes 985 — — — 985 Repayment of fixed-rate notes (900 ) — — — (900 ) Other, net 63 (3 ) — — 60 Net cash used by financing activities (2,396 ) (3 ) — — (2,399 ) Net cash used by discontinued operations (40 ) — — — (40 ) Cash sweep/funding by parent 2,816 (1,719 ) (1,097 ) — — Net increase in cash and equivalents 676 — (27 ) — 649 Cash and equivalents at beginning of year 1,254 — 1,080 — 2,334 Cash and equivalents at end of year $ 1,930 $ — $ 1,053 $ — $ 2,983 * Continuing operations only. CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Year Ended December 31, 2016 Parent Guarantors on a Combined Basis Other Subsidiaries on a Combined Basis Consolidating Adjustments Total Consolidated Net cash provided by operating activities* $ 217 $ 1,881 $ 65 $ — $ 2,163 Cash flows from investing activities: Capital expenditures (8 ) (336 ) (48 ) — (392 ) Other, net 7 32 (38 ) — 1 Net cash used by investing activities (1 ) (304 ) (86 ) — (391 ) Cash flows from financing activities: Purchases of common stock (1,996 ) — — — (1,996 ) Proceeds from fixed-rate notes 992 — — — 992 Dividends paid (911 ) — — — (911 ) Repayment of fixed-rate notes (500 ) — — — (500 ) Proceeds from stock option exercises 292 — — — 292 Other, net (45 ) (1 ) — — (46 ) Net cash used by financing activities (2,168 ) (1 ) — — (2,169 ) Net cash used by discontinued operations (54 ) — — — (54 ) Cash sweep/funding by parent 1,528 (1,576 ) 48 — — Net decrease in cash and equivalents (478 ) — 27 — (451 ) Cash and equivalents at beginning of year 1,732 — 1,053 — 2,785 Cash and equivalents at end of year $ 1,254 $ — $ 1,080 $ — $ 2,334 * Continuing operations only.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 01, 2019USD ($)	May 31, 2018USD ($)	Jan. 01, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | Segment	5
Number of defense segments | Segment	4
Loss to related to discontinued operations			$ 23
Trading securities	$ 0	$ 0
Other contract costs	135	448
Provision for income tax, net	(727)	(1,165)	(977)
Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issued					$ 7,500
Accounting Standards Update 2017-07 | Operating Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement, effect of change in operating results		59	10
Accounting Standards Update 2017-07 | Other Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement, effect of change in operating results		(59)	(10)
Accounting Standards Update 2016-02 | Minimum | Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability				$ 1,200
Operating lease right-of-use asset				1,200
Accounting Standards Update 2016-02 | Maximum | Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liability				1,600
Operating lease right-of-use asset				$ 1,600
Company-sponsored R & D, including product development costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Research and development expense	502	$ 521	418
Discontinued Operations, Disposed of by Sale
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax expense on sale of discontinued operations	$ 13
Information Technology
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fair value of reporting unit in excess of carrying amount (more than)	5.00%
Termination Of A - 12 Program
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loss to related to discontinued operations			$ 84
Retained Earnings | Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting pronouncement in period of adoption						$ 24
Retained Earnings | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting pronouncement in period of adoption						614
AOCI Attributable to Parent | Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting pronouncement in period of adoption						(24)
AOCI Attributable to Parent | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting pronouncement in period of adoption						$ (614)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Net Interest) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Interest expense	$ 374	$ 117	$ 99
Interest income	(18)	(14)	(8)
Interest expense, net	$ 356	$ 103	$ 91

Acquisitions and Divestitures_3

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Narrative) (Details) $ / shares in Units, $ in Millions	Apr. 03, 2018USD ($)$ / shares	Dec. 31, 2018USD ($)business	Dec. 31, 2017USD ($)business	Dec. 31, 2016USD ($)business
Business Acquisition [Line Items]
Total purchase price		$ 400	$ 400	$ 60
Amortization of intangible assets		270	$ 79	$ 88
CSRA
Business Acquisition [Line Items]
Total purchase price	$ 9,749
Intangible assets, net	2,066
Goodwill expected to be deductible for tax purposes	$ 490
Revenue of acquiree included in reported results since acquisition date		3,700
Operating earnings of acquiree included in reported results since acquisition date		400
Pre-tax earnings of acquiree included in reported results since acquisition date		430
Acquisition-related costs		$ 45
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Number of businesses acquired | business		5	4	2
Series of Individually Immaterial Business Acquisitions | Aerospace
Business Acquisition [Line Items]
Number of businesses acquired | business		2
Series of Individually Immaterial Business Acquisitions | Information Technology
Business Acquisition [Line Items]
Number of businesses sold | business		3
Common Stock | CSRA
Business Acquisition [Line Items]
Percentage of interest acquired	100.00%
Cash acquisition price (in dollars per share) | $ / shares	$ 41.25
Backlog and Customer Relationships | CSRA
Business Acquisition [Line Items]
Intangible assets, net	$ 2,100
Weighted-average life of acquired intangible assets	17 years
Percentage of aggregate value of acquired intangible assets to be amortized over 7 years	50.00%
Estimated period of amortization of 50% of the aggregate value of the intangible assets acquired	6 years
Operating costs and expenses and other income (expense) | CSRA
Business Acquisition [Line Items]
Acquisition-related costs		$ 75

Acquisitions and Divestitures_4

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Purchase Price and Fair Value of Net Assets Acquired) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Apr. 03, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Total purchase price		$ 400	$ 400	$ 60
CSRA
Business Acquisition [Line Items]
Cash consideration per CSRA share	$ 41.25
Cash paid to purchase outstanding CSRA shares	$ 6,825
Cash paid to extinguish CSRA debt	2,846
Cash settlement of outstanding CSRA stock options and restricted stock units	78
Total purchase price	$ 9,749
CSRA | CSRA
Business Acquisition [Line Items]
CSRA shares outstanding (in millions)	165.4

Acquisitions and Divestitures_5

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Fair Value of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Apr. 03, 2018	Apr. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 19,594		$ 11,955	$ 11,914	$ 11,445
CSRA
Business Acquisition [Line Items]
Cash and equivalents		$ 45
Accounts receivable		154
Unbilled receivables		510
Other current assets		301
Property, plant and equipment, net		673
Intangible assets, net		2,066
Goodwill		7,859
Other noncurrent assets		20
Total assets		11,628
Accounts payable		(139)
Customer advances and deposits		(151)
Current capital lease obligation		(51)
Other current liabilities		(404)
Noncurrent capital lease obligation		(207)
Noncurrent deferred tax liability		(376)
Other noncurrent liabilities		(551)
Total liabilities		(1,879)
Net assets acquired		$ 9,749

Acquisitions and Divestitures_6

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Pro Forma Information) (Details) - CSRA - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Revenue	$ 37,534	$ 35,828
Earnings from continuing operations	$ 3,390	$ 2,982
Diluted earnings per share from continuing operations	$ 11.33	$ 9.79

Acquisitions and Divestitures_7

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Changes In Goodwill) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
		Apr. 01, 2018		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill, beginning of period		$ 11,914		$ 11,955		$ 11,445
Acquisitions/divestitures		16	[1]	7,821		296	[1]
Other		25	[2]	(182)		173	[2]
Change in reporting unit composition				0
Goodwill, end of period		11,955		19,594		11,914
Aerospace
Goodwill [Roll Forward]
Goodwill, beginning of period		2,638	[3]	2,678	[3]	2,537
Acquisitions/divestitures	[1]	0		183		28
Other	[2]	40		(48)		73
Change in reporting unit composition	[4]			0
Goodwill, end of period		2,678	[3]	2,813	[5]	2,638	[3]
Combat Systems
Goodwill [Roll Forward]
Goodwill, beginning of period		2,677	[3]	2,663	[3]	2,598
Acquisitions/divestitures	[1]	0		30		0
Other	[2]	(14)		(60)		79
Change in reporting unit composition	[4]			0
Goodwill, end of period		2,663	[3]	2,633	[5]	2,677	[3]
Information Systems and Technology
Goodwill [Roll Forward]
Goodwill, beginning of period	[3]	6,302		6,317		6,013
Acquisitions/divestitures	[1]	16		0		268
Other	[2]	(1)		0		21
Change in reporting unit composition	[4]			(6,317)
Goodwill, end of period		6,317	[3]	0	[5]	6,302	[3]
Accumulated impairment loss		1,900				1,900		$ 1,900
Information Technology
Goodwill [Roll Forward]
Goodwill, beginning of period	[3]	0		0		0
Acquisitions/divestitures	[1]	0		7,601		0
Other	[2]	0		(55)		0
Change in reporting unit composition	[4]			2,076
Goodwill, end of period		0	[3]	9,622	[5]	0	[3]
Accumulated impairment loss				536
Mission Systems
Goodwill [Roll Forward]
Goodwill, beginning of period		0	[3]	0	[3]	0
Acquisitions/divestitures	[1]	0		7		0
Other	[2]	0		(19)		0
Change in reporting unit composition	[4]			4,241
Goodwill, end of period		0	[3]	4,229	[5]	0	[3]
Accumulated impairment loss				1,300
Marine Systems
Goodwill [Roll Forward]
Goodwill, beginning of period		297	[3]	297	[3]	297
Acquisitions/divestitures	[1]	0		0		0
Other	[2]	0		0		0
Change in reporting unit composition	[4]			0
Goodwill, end of period		$ 297	[3]	$ 297	[5]	$ 297	[3]
[1]	Includes adjustments during the purchase price allocation period. Activity in the first quarter of 2018 and the nine-month period ended December 31, 2018, also includes an allocation of goodwill associated with the sale of the commercial health products business and an allocation of goodwill associated with the sale of a public-facing contact-center business, respectively, as discussed above.
[2]	Consists primarily of adjustments for foreign currency translation. Activity in the nine-month period ended December 31, 2018, also includes an allocation of goodwill in our Information Technology reporting unit associated with certain operations classified as held for sale on the Consolidated Balance Sheet on December 31, 2018.
[3]	Goodwill in the Information Systems and Technology reporting unit is net of $1.9 billion of accumulated impairment losses.
[4]	Concurrent with the acquisition of CSRA, we reorganized our Information Systems and Technology operating segment into the Information Technology and Mission Systems segments. See Note A for further discussion of the segment reorganization. This reorganization similarly changed the composition of our reporting units. Accordingly, goodwill of the Information Systems and Technology reporting unit was reassigned to the Information Technology and Mission Systems reporting units using a relative fair value allocation approach as of the date of the reorganization.
[5]	Goodwill in the Information Technology and Mission Systems reporting units is net of $536 and $1.3 billion of accumulated impairment losses, respectively.

Acquisitions and Divestitures_8

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	$ 4,564	$ 2,441
Accumulated Amortization		(1,979)	(1,739)
Net Carrying Amount		2,585	702
Contract and Program Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1],[2]	3,771	1,684
Accumulated Amortization	[2]	(1,531)	(1,320)
Net Carrying Amount		2,240	364
Tradenames and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	469	465
Accumulated Amortization		(177)	(160)
Net Carrying Amount		292	305
Technology and Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	165	137
Accumulated Amortization		(116)	(105)
Net Carrying Amount		49	32
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	159	155
Accumulated Amortization		(155)	(154)
Net Carrying Amount		$ 4	$ 1
[1]	hange in gross carrying amounts consists primarily of adjustments for acquired intangible assets and foreign currency translation.
[2]	onsists of acquired backlog and probable follow-on work and associated customer relationships.

Acquisitions and Divestitures_9

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Amortization Life of Intangible Assets) (Details)	12 Months Ended
	Dec. 31, 2018
Contract and Program Intangible Assets | Minimum
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	7 years
Contract and Program Intangible Assets | Maximum
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	30 years
Tradenames and Trademarks
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	30 years
Technology and Software | Minimum
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	5 years
Technology and Software | Maximum
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	20 years
Other Intangible Assets | Minimum
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	2 years
Other Intangible Assets | Maximum
Finite-Lived Intangible Assets [Line Items]
Range of Amortization Life	7 years

Acquisitions and Divestiture_10

Acquisitions and Divestitures, Goodwill, and Intangible Assets (Amortization Expense of Intagible Assets) (Details) $ in Millions	Dec. 31, 2018USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,019	$ 280
2,020	265
2,021	217
2,022	192
2,023	$ 175

Revenue (Additional Information

Revenue (Additional Information) (Details) contract in Thousands, $ in Billions	12 Months Ended
	Dec. 31, 2018USD ($)contract	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Number of active contracts | contract	11
Revenue recognized in contract liability | $	$ 4.3	$ 4.3	$ 4.2
Transferred over Time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, percentage from products and services transferred to customers	74.00%	71.00%	72.00%
Transferred at Point in Time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, percentage from products and services transferred to customers	26.00%	29.00%	28.00%

Revenue (Remaining Performance

Revenue (Remaining Performance Obligations to be Recognized as Revenue) (Details) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total backlog		$ 63.2
Revenue, remaining performance obligation, percentage recognized		40.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period		1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total backlog	$ 67.9
Revenue, remaining performance obligation, percentage recognized	45.00%	40.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue, remaining performance obligation, percentage recognized	35.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	2 years

Revenue (Impact of Adjustments

Revenue (Impact of Adjustments in Contract Estimates) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 36,193	$ 30,973	$ 30,561
Operating earnings	$ 4,457	$ 4,236	$ 3,744
Diluted earnings per share	$ 11.18	$ 9.56	$ 8.29
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 377	$ 292	$ 95
Operating earnings	$ 345	$ 323	$ 16
Diluted earnings per share	$ 0.91	$ 0.69	$ 0.03

Revenue (Revenue by Major Produ

Revenue (Revenue by Major Products and Services) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from External Customer [Line Items]
Revenue	$ 36,193	$ 30,973	$ 30,561
Aerospace
Revenue from External Customer [Line Items]
Revenue	8,455	8,129	7,815
Aerospace | Aircraft manufacturing and completions
Revenue from External Customer [Line Items]
Revenue	6,226	6,320	6,074
Aerospace | Aircraft services
Revenue from External Customer [Line Items]
Revenue	2,096	1,743	1,625
Aerospace | Pre-owned aircraft
Revenue from External Customer [Line Items]
Revenue	133	66	116
Combat Systems
Revenue from External Customer [Line Items]
Revenue	6,241	5,949	5,530
Combat Systems | Military vehicles
Revenue from External Customer [Line Items]
Revenue	4,027	3,731	3,378
Combat Systems | Weapons, armament and munitions
Revenue from External Customer [Line Items]
Revenue	1,798	1,633	1,517
Combat Systems | Engineering and other services
Revenue from External Customer [Line Items]
Revenue	416	585	635
Information Technology
Revenue from External Customer [Line Items]
Revenue	8,269	4,410	4,428
Information Technology | Information technology services
Revenue from External Customer [Line Items]
Revenue	8,269	4,410	4,428
Mission Systems
Revenue from External Customer [Line Items]
Revenue	4,726	4,481	4,716
Mission Systems | C4ISR solutions
Revenue from External Customer [Line Items]
Revenue	4,726	4,481	4,716
Marine Systems
Revenue from External Customer [Line Items]
Revenue	8,502	8,004	8,072
Marine Systems | Nuclear-powered submarines
Revenue from External Customer [Line Items]
Revenue	5,712	5,175	5,264
Marine Systems | Surface ships
Revenue from External Customer [Line Items]
Revenue	1,872	1,607	1,648
Marine Systems | Repair and other services
Revenue from External Customer [Line Items]
Revenue	$ 918	$ 1,222	$ 1,160

Revenue (Revenue by Contract Ty

Revenue (Revenue by Contract Type) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Major Customer [Line Items]
Revenue	$ 36,193	$ 30,973	$ 30,561
Aerospace
Revenue, Major Customer [Line Items]
Revenue	8,455	8,129	7,815
Combat Systems
Revenue, Major Customer [Line Items]
Revenue	6,241	5,949	5,530
Information Technology
Revenue, Major Customer [Line Items]
Revenue	8,269	4,410	4,428
Mission Systems
Revenue, Major Customer [Line Items]
Revenue	4,726	4,481	4,716
Marine Systems
Revenue, Major Customer [Line Items]
Revenue	8,502	8,004	8,072
Fixed-price
Revenue, Major Customer [Line Items]
Revenue	24,606	21,320	20,945
Fixed-price | Aerospace
Revenue, Major Customer [Line Items]
Revenue	7,600	7,479	7,208
Fixed-price | Combat Systems
Revenue, Major Customer [Line Items]
Revenue	5,406	5,090	4,629
Fixed-price | Information Technology
Revenue, Major Customer [Line Items]
Revenue	3,396	1,465	1,514
Fixed-price | Mission Systems
Revenue, Major Customer [Line Items]
Revenue	2,711	2,478	2,737
Fixed-price | Marine Systems
Revenue, Major Customer [Line Items]
Revenue	5,493	4,808	4,857
Cost-reimbursement
Revenue, Major Customer [Line Items]
Revenue	9,087	8,152	8,153
Cost-reimbursement | Aerospace
Revenue, Major Customer [Line Items]
Revenue	0	0	0
Cost-reimbursement | Combat Systems
Revenue, Major Customer [Line Items]
Revenue	800	823	865
Cost-reimbursement | Information Technology
Revenue, Major Customer [Line Items]
Revenue	3,422	2,305	2,262
Cost-reimbursement | Mission Systems
Revenue, Major Customer [Line Items]
Revenue	1,861	1,838	1,822
Cost-reimbursement | Marine Systems
Revenue, Major Customer [Line Items]
Revenue	3,004	3,186	3,204
Time-and-materials
Revenue, Major Customer [Line Items]
Revenue	2,500	1,501	1,463
Time-and-materials | Aerospace
Revenue, Major Customer [Line Items]
Revenue	855	650	607
Time-and-materials | Combat Systems
Revenue, Major Customer [Line Items]
Revenue	35	36	36
Time-and-materials | Information Technology
Revenue, Major Customer [Line Items]
Revenue	1,451	640	652
Time-and-materials | Mission Systems
Revenue, Major Customer [Line Items]
Revenue	154	165	157
Time-and-materials | Marine Systems
Revenue, Major Customer [Line Items]
Revenue	$ 5	$ 10	$ 11

Revenue (Revenue by Customer) (

Revenue (Revenue by Customer) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Major Customer [Line Items]
Revenue	$ 36,193	$ 30,973	$ 30,561
U.S. Government - Department of Defense
Revenue, Major Customer [Line Items]
Revenue	17,752	15,441	15,080
U.S. Government - Non Department of Defense
Revenue, Major Customer [Line Items]
Revenue	5,228	2,904	2,883
U.S. Government - Foreign Military Sales
Revenue, Major Customer [Line Items]
Revenue	626	676	713
U.S. Government
Revenue, Major Customer [Line Items]
Revenue	23,606	19,021	18,676
U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	4,972	4,498	4,484
Non-U.S. Government
Revenue, Major Customer [Line Items]
Revenue	4,002	3,442	3,663
Non-U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	3,613	4,012	3,738
Aerospace
Revenue, Major Customer [Line Items]
Revenue	8,455	8,129	7,815
Aerospace | U.S. Government - Department of Defense
Revenue, Major Customer [Line Items]
Revenue	236	189	231
Aerospace | U.S. Government - Non Department of Defense
Revenue, Major Customer [Line Items]
Revenue	0	0	0
Aerospace | U.S. Government - Foreign Military Sales
Revenue, Major Customer [Line Items]
Revenue	98	42	130
Aerospace | U.S. Government
Revenue, Major Customer [Line Items]
Revenue	334	231	361
Aerospace | U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	4,175	3,885	3,501
Aerospace | Non-U.S. Government
Revenue, Major Customer [Line Items]
Revenue	551	210	496
Aerospace | Non-U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	3,395	3,803	3,457
Combat Systems
Revenue, Major Customer [Line Items]
Revenue	6,241	5,949	5,530
Combat Systems | U.S. Government - Department of Defense
Revenue, Major Customer [Line Items]
Revenue	2,903	2,702	2,274
Combat Systems | U.S. Government - Non Department of Defense
Revenue, Major Customer [Line Items]
Revenue	8	8	7
Combat Systems | U.S. Government - Foreign Military Sales
Revenue, Major Customer [Line Items]
Revenue	317	374	333
Combat Systems | U.S. Government
Revenue, Major Customer [Line Items]
Revenue	3,228	3,084	2,614
Combat Systems | U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	251	220	287
Combat Systems | Non-U.S. Government
Revenue, Major Customer [Line Items]
Revenue	2,698	2,580	2,520
Combat Systems | Non-U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	64	65	109
Information Technology
Revenue, Major Customer [Line Items]
Revenue	8,269	4,410	4,428
Information Technology | U.S. Government - Department of Defense
Revenue, Major Customer [Line Items]
Revenue	3,291	1,802	1,781
Information Technology | U.S. Government - Non Department of Defense
Revenue, Major Customer [Line Items]
Revenue	4,712	2,340	2,343
Information Technology | U.S. Government - Foreign Military Sales
Revenue, Major Customer [Line Items]
Revenue	22	22	23
Information Technology | U.S. Government
Revenue, Major Customer [Line Items]
Revenue	8,025	4,164	4,147
Information Technology | U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	163	214	259
Information Technology | Non-U.S. Government
Revenue, Major Customer [Line Items]
Revenue	81	32	8
Information Technology | Non-U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	0	0	14
Mission Systems
Revenue, Major Customer [Line Items]
Revenue	4,726	4,481	4,716
Mission Systems | U.S. Government - Department of Defense
Revenue, Major Customer [Line Items]
Revenue	3,224	3,027	3,287
Mission Systems | U.S. Government - Non Department of Defense
Revenue, Major Customer [Line Items]
Revenue	506	556	525
Mission Systems | U.S. Government - Foreign Military Sales
Revenue, Major Customer [Line Items]
Revenue	44	46	25
Mission Systems | U.S. Government
Revenue, Major Customer [Line Items]
Revenue	3,774	3,629	3,837
Mission Systems | U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	138	108	108
Mission Systems | Non-U.S. Government
Revenue, Major Customer [Line Items]
Revenue	662	607	613
Mission Systems | Non-U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	152	137	158
Marine Systems
Revenue, Major Customer [Line Items]
Revenue	8,502	8,004	8,072
Marine Systems | U.S. Government - Department of Defense
Revenue, Major Customer [Line Items]
Revenue	8,098	7,721	7,507
Marine Systems | U.S. Government - Non Department of Defense
Revenue, Major Customer [Line Items]
Revenue	2	0	8
Marine Systems | U.S. Government - Foreign Military Sales
Revenue, Major Customer [Line Items]
Revenue	145	192	202
Marine Systems | U.S. Government
Revenue, Major Customer [Line Items]
Revenue	8,245	7,913	7,717
Marine Systems | U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	245	71	329
Marine Systems | Non-U.S. Government
Revenue, Major Customer [Line Items]
Revenue	10	13	26
Marine Systems | Non-U.S. Commercial
Revenue, Major Customer [Line Items]
Revenue	$ 2	$ 7	$ 0

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Basic weighted average shares outstanding (shares)		295,262	299,172	304,707
Dilutive effect of stock options and restricted stock/RSUs (shares)	[1]	3,898	5,465	5,680
Diluted weighted average shares outstanding (shares)		299,160	304,637	310,387
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive outstanding options excluded from computation of earnings per share (shares)		3,143	1,547	4,201
[1]	Excludes outstanding options to purchase shares of common stock that had exercise prices in excess of the average market price of our common stock during the year and, therefore, the effect of including these options would be antidilutive. These options totaled 3,143 in 2018, 1,547 in 2017 and 4,201 in 2016.

Fair Value (Details)

Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets (liabilities)
Cash and equivalents	$ 23	$ 15
Available-for-sale debt securities	0
Available-for-sale debt securities		0
Equity securities	52	54
Other investments	0
Other investments		0
Cash flow hedges	0	0
Short- and long-term debt principal	0	0
Significant Other Observable Inputs (Level 2)
Financial assets (liabilities)
Cash and equivalents	6	5
Available-for-sale debt securities	121
Available-for-sale debt securities		117
Equity securities	0	0
Other investments	0
Other investments		0
Cash flow hedges	(69)	(105)
Short- and long-term debt principal	(12,346)	(3,974)
Significant Unobservable Inputs (Level 3)
Financial assets (liabilities)
Cash and equivalents	0	0
Available-for-sale debt securities	0
Available-for-sale debt securities		0
Equity securities	0	0
Other investments	4
Other investments		4
Cash flow hedges	0	0
Short- and long-term debt principal	0	0
Carrying Value
Financial assets (liabilities)
Cash and equivalents	29	20
Available-for-sale debt securities	121
Available-for-sale debt securities		117
Equity securities	52	54
Other investments	4
Other investments		4
Cash flow hedges	(69)	(105)
Short- and long-term debt principal	(12,518)	(4,032)
Fair Value
Financial assets (liabilities)
Cash and equivalents	29	20
Available-for-sale debt securities	121
Available-for-sale debt securities		117
Equity securities	52	54
Other investments	4
Other investments		4
Cash flow hedges	(69)	(105)
Short- and long-term debt principal	$ (12,346)	$ (3,974)

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Unfavorable impact in tax provision from change in tax law	$ 0	$ 119	$ 0
Deferred tax asset amount related to accumulated other comprehensive income	1,000
Investment of U.S. government accounts receivable in the CCF	483	$ 692
Net operating loss carryforwards	1,000
Tax credit carryforwards	$ 135
Possible chance of tax position sustainable, percentage	50.00%
Tax positions for which it is reasonably possible that the unrecognized tax benefits will significantly increase or decrease	$ 0

Income Taxes (Net Provision For

Income Taxes (Net Provision For Income Taxes For Continuing Operations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
U.S. federal	$ 587	$ 656	$ 698
State	48	31	24
International	95	77	71
Total current	730	764	793
Deferred:
U.S. federal	(37)	215	140
State	8	7	7
International	26	60	37
Adjustment for enacted change in U.S. tax law	0	119	0
Total deferred	(3)	401	184
Provision for income taxes, net	727	1,165	977
Net income tax payments	$ 532	$ 617	$ 959

Income Taxes (Reconciliation Fr

Income Taxes (Reconciliation From Statutory Federal Income Tax Rate To Effective Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	21.00%	35.00%	35.00%
State tax on commercial operations, net of federal benefits	1.10%	0.60%	0.60%
Impact of international operations	0.60%	(4.50%)	(4.00%)
Domestic production deduction	(0.00%)	(1.50%)	(1.50%)
Foreign derived intangible income	(1.20%)	(0.00%)	(0.00%)
Equity-based compensation	(1.10%)	(2.60%)	(2.30%)
Domestic tax credits	(1.10%)	(0.80%)	(0.90%)
Contract close-outs	(0.50%)	(0.00%)	(0.00%)
Adoption impact of enacted change in U.S. tax law	0.00%	2.90%	0.00%
Other, net	(1.00%)	(0.50%)	(0.20%)
Effective income tax rate	17.80%	28.60%	26.70%

Income Taxes (Tax Effects Of Te

Income Taxes (Tax Effects Of Temporary Differences Between Reported Earnings And Taxable Earnings) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Retirement benefits	$ 1,055	$ 935
Tax loss and credit carryforwards	393	437
Salaries and wages	160	137
Workers' compensation	138	139
Other	351	335
Deferred assets	2,097	1,983
Valuation allowance	(336)	(402)
Net deferred assets	1,761	1,581
Intangible assets	(1,061)	(688)
Contract accounting methods	(530)	(500)
Property, plant and equipment	(265)	(182)
Capital Construction Fund qualified ships	(160)	(159)
Other	(284)	(221)
Deferred liabilities	(2,300)	(1,750)
Net deferred tax liability	$ (539)	$ (169)

Income Taxes (Net Deferred Tax

Income Taxes (Net Deferred Tax Asset (Liability)) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Noncurrent deferred tax asset	$ 38	$ 75
Noncurrent deferred tax liability	(577)	(244)
Net deferred tax liability	$ (539)	$ (169)

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable [Line Items]
Total accounts receivable	$ 3,759	$ 3,617
Non-U.S. Government
Accounts Receivable [Line Items]
Total accounts receivable	2,035	2,228
Receivables related to long-term production programs	1,900	2,100
Receivables related to long-term production programs, net of customer advances	(338)	(284)
U.S. Government
Accounts Receivable [Line Items]
Total accounts receivable	1,189	971
Commercial
Accounts Receivable [Line Items]
Total accounts receivable	$ 535	$ 418

Unbilled Receivables (Details)

Unbilled Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Contractors [Abstract]
Unbilled revenue	$ 27,908	$ 21,845
Advances and progress billings	(21,332)	(16,605)
Net unbilled receivables	$ 6,576	$ 5,240

Unbilled Receivables (Narrative

Unbilled Receivables (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivable	$ 27,908	$ 21,845
G&A costs in unbilled revenue	381	$ 282
Combat Systems
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivable	$ 1,900

Inventory (Details)

Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Work in process	$ 4,357	$ 3,872
Raw materials	1,504	1,357
Finished goods	33	51
Pre-owned aircraft	83	23
Total inventories	$ 5,977	$ 5,303

Property, Plant And Equipment_3

Property, Plant And Equipment, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Machinery and equipment	$ 5,534	$ 4,736
Buildings and improvements	3,011	2,837
Land and improvements	386	357
Construction in process	472	307
Total property, plant and equipment	9,403	8,237
Accumulated depreciation	(5,055)	(4,720)
Property, plant and equipment, net	$ 4,348	$ 3,517
Buildings And Improvements
Property, Plant and Equipment [Line Items]
Depreciable life, maximum, years	50 years
Machinery And Equipment
Property, Plant and Equipment [Line Items]
Depreciable life, maximum, years	30 years

Debt (Details)

Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt principal	$ 12,518	$ 4,032
Less unamortized debt issuance costs and discounts	101	50
Total debt	12,417	3,982
Short-term debt and current portion of long-term debt	973	2
Long-term debt	11,444	3,980
Commercial Paper
Debt Instrument [Line Items]
Short-term debt	$ 850	0
Weighed average interest rate	2.568%
Fixed Rate Notes Due May 2020
Debt Instrument [Line Items]
Long-term debt	$ 2,000	0
Interest rate	2.875%
Fixed Rate Notes Due May 2021
Debt Instrument [Line Items]
Long-term debt	$ 2,000	0
Interest rate	3.00%
Fixed Rate Notes Due July 2021
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Interest rate	3.875%
Fixed Rate Notes Due November 2022
Debt Instrument [Line Items]
Long-term debt	$ 1,000	1,000
Interest rate	2.25%
Fixed Rate Notes Due May 2023
Debt Instrument [Line Items]
Long-term debt	$ 750	0
Interest rate	3.375%
Fixed Rate Notes Due August 2023
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Interest rate	1.875%
Fixed Rate Notes Due November 2024
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Interest rate	2.375%
Fixed Rate Notes Due May 2025
Debt Instrument [Line Items]
Long-term debt	$ 750	0
Interest rate	3.50%
Fixed Rate Notes Due August 2026
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Interest rate	2.125%
Fixed Rate Notes Due November 2027
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Interest rate	2.625%
Fixed Rate Notes Due May 2028
Debt Instrument [Line Items]
Long-term debt	$ 1,000	0
Interest rate	3.75%
Fixed Rate Notes Due November 2042
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Interest rate	3.60%
Floating Rate Notes Due May 2020 | LIBOR
Debt Instrument [Line Items]
Long-term debt	$ 500	0
Basis spread on variable rate	0.29%
Floating Rate Notes Due May 2021 | LIBOR
Debt Instrument [Line Items]
Long-term debt	$ 500	0
Basis spread on variable rate	0.38%
Other Debt Securities
Debt Instrument [Line Items]
Long-term debt	$ 168	$ 32
Other interest rate	Various

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Apr. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	May 31, 2018
Debt Outstanding [Line Items]
Interest payments		$ 312	$ 93	$ 83
Percentage of owned subsidiaries guaranteed fixed- and floating-rate notes		100.00%
Credit facility, maximum borrowing capacity		$ 5,000
Credit Facility | 364-day Committed Bank Credit Facility
Debt Outstanding [Line Items]
Credit facility, maximum borrowing capacity		$ 2,000
Debt instrument term		364 days
Credit Facility | 364-day Committed Bank Credit Facility | CSRA
Debt Outstanding [Line Items]
Borrowings from line of credit	$ 7,500
Commercial Paper
Debt Outstanding [Line Items]
Commercial paper outstanding		$ 850	0
Weighed average interest rate		2.568%
LIBOR | Floating Rate Notes Due May 2020
Debt Outstanding [Line Items]
Long-term debt		$ 500	0
LIBOR | Floating Rate Notes Due May 2021
Debt Outstanding [Line Items]
Long-term debt		500	$ 0
Notes
Debt Outstanding [Line Items]
Debt issued					$ 7,500
Notes | LIBOR | Floating Rate Notes Due May 2020
Debt Outstanding [Line Items]
Long-term debt					500
Notes | LIBOR | Floating Rate Notes Due May 2021
Debt Outstanding [Line Items]
Long-term debt					$ 500
Credit Facility | Multi-year Facility Expiring November 2020
Debt Outstanding [Line Items]
Credit facility, maximum borrowing capacity		1,000
Credit Facility | Multi Year Facility Expiring March 2023
Debt Outstanding [Line Items]
Credit facility, maximum borrowing capacity		$ 2,000

Debt Debt (Aggregate Amounts Of

Debt Debt (Aggregate Amounts Of Scheduled Maturities Of Debt For The Next Five Years) (Details) $ in Millions	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2,019	$ 973
2,020	2,501
2,021	3,002
2,022	1,002
2,023	1,252
Thereafter	3,788
Total debt	$ 12,518

Other Liabilities (Details)

Other Liabilities (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Salaries and wages		$ 952	$ 786
Retirement benefits		272	295
Workers' compensation		244	320
Fair value of cash flow hedges		141	180
Other	[1]	1,708	1,317
Total other current liabilities		3,317	2,898
Retirement benefits		4,422	4,408
Customer deposits on commercial contracts		726	814
Deferred income taxes		577	244
Other	[2]	1,768	1,066
Total other liabilities		$ 7,493	$ 6,532
[1]	Consists primarily of dividends payable, taxes payable, capital lease obligations, environmental remediation reserves, warranty reserves, deferred revenue and supplier contributions in the Aerospace segment, liabilities of discontinued operations, and insurance-related costs.
[2]	Consists primarily of capital lease obligations, warranty reserves, workers’ compensation liabilities and liabilities of discontinued operations.

Shareholders' Equity - (Narrati

Shareholders' Equity - (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 05, 2018
Class of Stock [Line Items]
Authorized capital stock, common stock (shares)	500,000,000
Common stock, par value	$ 1
Authorized capital stock, preferred stock (shares)	50,000,000
Preferred stock, par value	$ 1
Common stock, issued (shares)	481,880,634	481,880,634
Common stock, outstanding (shares)	288,698,149	296,895,608
Preferred stock, outstanding (shares)	0	0
Share repurchased, additional amount authorized (shares)				10,000,000
Stock repurchased (shares)	10,100,000	7,800,000	14,200,000
Shares repurchased	$ 1,806	$ 1,533	$ 2,031
Shares remaining under a prior authorization	7,500,000
Percent of total shares outstanding authorized for repurchase	3.00%
Dividends declared per share	$ 3.72	$ 3.36	$ 3.04
Dividends paid	$ 1,075	$ 986	$ 911
Pretax recognized actuarial losses	355	358	340
Pretax amortization of prior service credit	$ 50	$ 69	$ 74
Restricted Stock
Class of Stock [Line Items]
Unvested restricted stock (shares)	686,921

Shareholders' Equity - (Accumul

Shareholders' Equity - (Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (2,820)	$ (3,387)	$ (3,283)
Cumulative effect adjustment	(638)
Other comprehensive loss, pretax	(325)	718	(122)
Benefit from (provision for) income tax, net	5	(151)	18
Other comprehensive (loss) income, net amount	(320)	567	(104)
Ending balance	(3,778)	(2,820)	(3,387)
Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(94)	(345)	(487)
Cumulative effect adjustment	(4)
Other comprehensive loss, pretax	36	341	191
Benefit from (provision for) income tax, net	(9)	(90)	(49)
Other comprehensive (loss) income, net amount	27	251	142
Ending balance	(71)	(94)	(345)
Unrealized Gains (Losses) On Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	19	14	20
Cumulative effect adjustment	(19)
Other comprehensive loss, pretax	0	9	(9)
Benefit from (provision for) income tax, net	0	(4)	3
Other comprehensive (loss) income, net amount	0	5	(6)
Ending balance	0	19	14
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	402	69	181
Cumulative effect adjustment	0
Other comprehensive loss, pretax	(300)	348	(112)
Benefit from (provision for) income tax, net	0	(15)	0
Other comprehensive (loss) income, net amount	(300)	333	(112)
Ending balance	102	402	69
Changes In Retirement Plans' Funded Status
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(3,147)	(3,125)	(2,997)
Cumulative effect adjustment	(615)
Other comprehensive loss, pretax	(61)	20	(192)
Benefit from (provision for) income tax, net	14	(42)	64
Other comprehensive (loss) income, net amount	(47)	(22)	(128)
Ending balance	$ (3,809)	$ (3,147)	$ (3,125)

Derivative Financial Instrume_2

Derivative Financial Instruments And Hedging Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Average maturity of foreign currency forward contracts, in years	2 years
Cash and equivalents	$ 963	$ 2,983	$ 2,334	$ 2,785
Marketable securities held in trust	202
Derivative notional amount	$ 5,800	$ 4,300
Maximum
Derivative Instruments, Gain (Loss) [Line Items]
Maturity of fixed-income securities, in years	5 years

Commitments And Contingencies_2

Commitments And Contingencies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)agreementemployee	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Commitments and Contingencies [Line Items]
Total expense under operating leases	$ 380	$ 309	$ 307
Letters of credit	$ 1,700
Number of company-negotiated labor agreements | agreement	94
Number of collective agreements expected to be renegotiated | agreement	21
Number of employees covered by expected renegotiated collective agreements | employee	5,500
Gross amount of assets under capital leases	$ 485	19
Accumulated amortization of assets under capital lease	5,055	4,720
Assets Held under Capital Leases
Commitments and Contingencies [Line Items]
Accumulated amortization of assets under capital lease	$ 61	$ 3
Unionized Employees Concentration Risk
Commitments and Contingencies [Line Items]
Percent of employees represented by labor organizations	20.00%
Maximum | Aerospace
Commitments and Contingencies [Line Items]
Period preceding delivery of aircraft to customer fair market value of trade-in aircraft is established, days, maximum	45 days

Commitments And Contingencies_3

Commitments And Contingencies (Schedule of Future Minimum Operating Lease Payments Due) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 297
2,020	234
2,021	196
2,022	154
2,023	110
Thereafter	698
Total minimum lease payments	$ 1,689

Commitments And Contingencies_4

Commitments And Contingencies (Changes in Product Warranty Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balance	$ 467	$ 474	$ 434
Warranty expense	129	146	155
Payments	(102)	(123)	(100)
Adjustments	(14)	(30)	(15)
Ending balance	$ 480	$ 467	$ 474

Commitments And Contingencies_5

Commitments And Contingencies (Schedule of Future Minimum Capital Lease Payments Due) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 92
2,020	84
2,021	78
2,022	79
2,023	30
Thereafter	70
Total future minimum lease payments	433
Less amount representing interest	95
Less amount representing executory costs	19
Present value of net minimum lease payments	319
Less current maturities of capital lease liability	64
Non-current capital lease liability	$ 255

Equity Compensation Plans (Narr

Equity Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of shares available for grant (shares)	28
Weighted average fair value per option granted	$ 37.42	$ 33.09	$ 22.11
Stock option expense reduced operating earnings	$ 57	$ 53	$ 39
Stock option expense earnings per share	$ 0.15	$ 0.11	$ 0.08
Total intrinsic value of options exercised	$ 147	$ 215	$ 263
Stock Options
Awards vesting period	3 years
Awards expiration period	10 years
Unrecognized compensation cost related to stock options	$ 73
Recognition period for unrecognized compensation cost for restricted stock	1 year 10 months 7 days
Stock Options | Share-based Compensation Award, Vesting In Second Year
Percentage of stock options vesting in a period of one year	50.00%
Stock Options | Share-based Compensation Award, Vesting In Third Year
Percentage of stock options vesting in a period of one year	50.00%
Restricted Stock and Restricted Stock Units (RSUs)
Awards vesting period	3 years
Stock option expense reduced operating earnings	$ 83	$ 70	$ 56
Stock option expense earnings per share	$ 0.22	$ 0.15	$ 0.12
Unrecognized compensation cost related to stock options	$ 53
Recognition period for unrecognized compensation cost for restricted stock	1 year 7 months 10 days
Fair value of vesting shares	$ 242	$ 200	$ 68

Equity Compensation Plans (Sche

Equity Compensation Plans (Schedule Of Equity Based Compensation Expense) (Details) - 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 options	$ 45	$ 34	$ 25
Restricted stock/RSUs	65	46	36
Total equity-based compensation expense, net of tax	$ 110	$ 80	$ 61

Equity Compensation Plans (Sc_2

Equity Compensation Plans (Schedule Of Assumption Of Fair Value Options On The Date Of Grant Using Black-Scholes Option Pricing Model) (Details) - Stock Options	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	17.60%	17.30%	19.10%
Expected volatility, maximum	18.20%	19.40%	20.00%
Weighted average expected volatility	17.60%	19.40%	20.00%
Expected term (in months)	68 months	68 months	70 months
Risk - free interest rate, minimum	2.60%	2.00%	1.50%
Risk - free interest rate, maximum	2.90%	2.20%	1.60%
Expected dividend yield	1.80%	1.80%	2.00%

Equity Compensation Plans (Summ

Equity Compensation Plans (Summary Of Stock Option Activity) (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding balance - shares under option, beginning | shares	10,620,389
Granted - shares under option | shares	1,730,430
Exercised - shares under option | shares	(1,388,110)
Forfeited/cancelled - shares under option | shares	(197,514)
Outstanding balance - shares under option, ending | shares	10,765,195
Vested and expected to vest on December 31, 2017 - shares under option | shares	10,595,953
Exercisable on December 31, 2017 - shares under option | shares	6,119,560
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding balance - weighted average exercise price, beginning | $ / shares	$ 126.08
Granted - weighted average exercise price | $ / shares	223.06
Exercised - weighted average exercise price | $ / shares	104.48
Forfeited/cancelled - weighted average exercise price | $ / shares	182.08
Outstanding balance - weighted average exercise price, ending | $ / shares	143.43
Vested and expected to vest on December 31, 2017 - weighted average exercise price | $ / shares	142.32
Exercisable on December 31, 2017 - weighted average exercise price | $ / shares	$ 109.19

Equity Compensation Plans (Sc_3

Equity Compensation Plans (Schedule Of Stock Options' Intrinsic Value And Remaining Contractual Term) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding - weighted average remaining contractual term (in years)	5 years 6 months
Vested and expected to vest - weighted average remaining contractual term (in years)	5 years 5 months 10 days
Exercisable - weighted average remaining contractual term (in years)	3 years 5 months 10 days
Outstanding - aggregate intrinsic value	$ 320
Vested and expected to vest - aggregate intrinsic value	319
Exercisable - aggregate intrinsic value	$ 294

Equity Compensation Plans (Su_2

Equity Compensation Plans (Summary Of Restricted Stock And Restricted Stock Unit Activity) (Details) - Restricted Stock and Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested - beginning balance (shares) | shares	1,983,173
Granted (shares) | shares	482,700
Vested (shares) | shares	(1,163,702)
Forfeited (shares) | shares	(39,895)
Nonvested - ending balance (shares) | shares	1,262,276
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonvested, weighted average grant-date fair value - beginning balance | $ / shares	$ 135.38
Granted, weighted average grant-date fair value | $ / shares	204.97
Vested, weighted average grant-date fair value | $ / shares	122.59
Forfeited, weighted average grant-date fair value | $ / shares	195.99
Nonvested, weighted average grant-date fair value - ending balance | $ / shares	$ 171.62

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) shares in Millions, $ in Millions	Jan. 01, 2019	Dec. 31, 2018USD ($)planshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)
Compensation And Retirement Disclosure Line Items
Defined contribution plan, cost recognized		$ 302	$ 274	$ 261
Common stock, shares held in employee trust (shares) | shares		21	21
Percentage of defined contribution plans held from outstanding shares		7.00%	7.00%
Number of noncontributory defined benefit pension plans covering government business employees | plan		10
Number of contributory defined benefit pension plans covering government business employees | plan		5
Number of noncontributory defined benefit pension plans covering commercial business employees | plan		2
Number of contributory defined benefit pension plans covering commercial business employees | plan		4
Number of non-qualified supplemental executive plans | plan		1
Required employer contributions to defined benefit retirement plans during fiscal year		$ 315
Additional discretionary contributions made by employer to defined-benefit retirement plans		255
Employer future employer contributions to defined-benefit retirement plans during fiscal year		$ 570
Period in which the difference between the actual and expected return on plan assets for qualified plans are recognized in years		5 years
Expected change in long-term rate of return on assets			(0.75%)
Defined benefit plan, effect of one percentage point increase on service and interest cost components		$ 4
Defined benefit plan, effect of one percentage point decrease on service and interest cost components		(3)
Defined benefit plan, effect of one percentage point increase on accumulated postretirement benefit obligation		65
Defined benefit plan, effect of one percentage point decrease on accumulated postretirement benefit obligation		$ (52)
Percentage of pension plan assets held in a single trust for primary domestic government and commercial pension plans		75.00%
Redemption notice period		90 days
Unfunded commitments, amount		$ 0	$ 0
Scenario, Forecast
Compensation And Retirement Disclosure Line Items
Expected change in long-term rate of return on assets	(1.00%)
Pension Benefits
Compensation And Retirement Disclosure Line Items
Expected contribution to defined benefit contribution plans		190
Defined benefit plan, accumulated benefit obligation		$ 15,500	$ 13,900

Retirement Plans (Schedule Of B

Retirement Plans (Schedule Of Benefits To Be Paid From Retirement Plans Over The Next Ten Years) (Details) $ in Millions	Dec. 31, 2018USD ($)
Pension Benefits
Compensation And Retirement Disclosure Line Items
2,019	$ 816
2,020	846
2,021	873
2,022	899
2,023	927
2024-2028	4,947
Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
2,019	68
2,020	67
2,021	66
2,022	65
2,023	64
2024-2028	$ 296

Retirement Plans (Schedule of A

Retirement Plans (Schedule of Annual Pension and Other Post-Retirement Benefit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 180	$ 168	$ 173
Interest cost	532	453	456
Expected return on plan assets	(856)	(679)	(713)
Recognized net actuarial loss (gain)	359	362	343
Amortization of prior service credit	(46)	(66)	(68)
Annual benefit (credit) cost	169	238	191
Other Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	9	10
Interest cost	33	30	34
Expected return on plan assets	(40)	(34)	(33)
Recognized net actuarial loss (gain)	(4)	(4)	(3)
Amortization of prior service credit	(4)	(3)	(6)
Annual benefit (credit) cost	$ (5)	$ (2)	$ 2

Retirement Plans (Reconciliatio

Retirement Plans (Reconciliation Of Benefit Obligations And Plan Or Trust Assets And Resulting Funded Status Of Defined Benefit Retirement Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Change in Benefit Obligation
Benefit obligation at beginning of year	$ (14,212)	$ (13,022)
Service cost	(180)	(168)	$ (173)
Interest cost	(532)	(453)	(456)
Acquisitions	(2,758)	0
Amendments	15	1
Actuarial gain (loss)	1,183	(1,098)
Settlement/curtailment/other	23	(58)
Benefits paid	741	586
Benefit obligation at end of year	(15,720)	(14,212)	(13,022)
Change in Plan/Trust Assets
Fair value of assets at beginning of year	10,130	8,980
Actual return on plan assets	(749)	1,469
Acquisitions	2,328	0
Employer contributions	571	199
Settlement/curtailment/other	(26)	56
Benefits paid	(722)	(574)
Fair value of assets at end of year	11,532	10,130	8,980
Funded status at end of year	(4,188)	(4,082)
Other Post-retirement Benefits
Change in Benefit Obligation
Benefit obligation at beginning of year	(996)	(1,005)
Service cost	(10)	(9)	(10)
Interest cost	(33)	(30)	(34)
Acquisitions	(62)	0
Amendments	0	0
Actuarial gain (loss)	78	(42)
Settlement/curtailment/other	21	27
Benefits paid	67	63
Benefit obligation at end of year	(935)	(996)	(1,005)
Change in Plan/Trust Assets
Fair value of assets at beginning of year	541	499
Actual return on plan assets	(4)	82
Acquisitions	77	0
Employer contributions	1	3
Settlement/curtailment/other	0	0
Benefits paid	(45)	(43)
Fair value of assets at end of year	570	541	$ 499
Funded status at end of year	$ (365)	$ (455)

Retirement Plans (Amounts Recog

Retirement Plans (Amounts Recognized On The Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current liabilities	$ (272)	$ (295)
Noncurrent liabilities	(4,422)	(4,408)
Pension Benefits
Noncurrent assets	67	133
Current liabilities	(131)	(145)
Noncurrent liabilities	(4,124)	(4,070)
Net liability recognized	(4,188)	(4,082)
Other Post-retirement Benefits
Noncurrent assets	74	33
Current liabilities	(141)	(150)
Noncurrent liabilities	(298)	(338)
Net liability recognized	$ (365)	$ (455)

Retirement Plans (Amounts Defer

Retirement Plans (Amounts Deferred In AOCL) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial loss (gain)	$ 4,959	$ 4,899
Prior service (credit) cost	(95)	(124)
Total amount recognized in AOCI, pre-tax	4,864	4,775
Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial loss (gain)	(37)	(5)
Prior service (credit) cost	1	(3)
Total amount recognized in AOCI, pre-tax	$ (36)	$ (8)

Retirement Plans (Reconciliat_2

Retirement Plans (Reconciliation Of The Change In AOCL For Defined-Benefit Retirement Plans) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amortization of:
Prior service credit (cost)		$ (50)	$ (69)	$ (74)
Change in AOCL, pretax		61	(20)	$ 192
Pension Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial loss (gain)		422	308
Prior service cost		(15)	(1)
Amortization of:
Net actuarial (loss) gain from prior years		(359)	(362)
Prior service credit (cost)		46	66
Other	[1]	(5)	7
Change in AOCL, pretax		89	18
Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial loss (gain)		(34)	(6)
Prior service cost		0	0
Amortization of:
Net actuarial (loss) gain from prior years		4	4
Prior service credit (cost)		4	3
Other	[1]	(2)	(39)
Change in AOCL, pretax		$ (28)	$ (38)
[1]	Includes foreign exchange translation, curtailment and other adjustments.

Retirement Plans (Amounts Def_2

Retirement Plans (Amounts Deferred In AOCL On The Consolidated Balance Sheet) (Details) $ in Millions	Dec. 31, 2018USD ($)
Pension Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial loss (gain)	$ 280
Prior service credit	(18)
Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Net actuarial loss (gain)	(8)
Prior service credit	$ (4)

Retirement Plans (Schedule Of_2

Retirement Plans (Schedule Of ABO That Exceeded The Plans' Assets) (Details) - Pension Benefits - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Compensation And Retirement Disclosure Line Items
PBO	$ (15,067)	$ (13,660)
ABO	(14,856)	(13,398)
Fair value of plan assets	$ 10,832	$ 9,526

Retirement Plans (Assumptions U

Retirement Plans (Assumptions Used To Determine Our Benefit Obligations And Net Periodic Benefit Costs) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Compensation And Retirement Disclosure Line Items
Benefit obligation discount rate	4.28%	3.62%
Rate of increase in compensation levels	2.79%	2.82%
Healthcare cost trend rate:
Weighted average used to determine net cost for the year ended, Discount rate	3.69%	4.19%	4.46%
Weighted averaged used to determine net cost for the year ended, Discount rate for service cost	3.51%	4.13%	4.42%
Weighted averaged used to determine net cost for the year ended, Discount rate for interest cost	3.34%	3.56%	3.71%
Weighted average used to determine net cost for the year ended, expected long-term rate of return on assets	7.45%	7.43%	8.14%
Weighed average rate of increase in compensation levels	2.79%	2.90%	3.39%
Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Benefit obligation discount rate	4.24%	3.64%
Healthcare cost trend rate:
Trend rate for next year	6.50%	6.50%
Ultimate trend rate	5.00%	5.00%
Year rate reaches ultimate trend rate	2,024	2,024
Weighted average used to determine net cost for the year ended, Discount rate	3.64%	4.11%	4.35%
Weighted averaged used to determine net cost for the year ended, Discount rate for service cost	3.79%	4.34%	4.52%
Weighted averaged used to determine net cost for the year ended, Discount rate for interest cost	3.27%	3.43%	3.53%
Weighted average used to determine net cost for the year ended, expected long-term rate of return on assets	7.75%	7.76%	7.81%

Retirement Plans (Hypothetical

Retirement Plans (Hypothetical Changes In The Discount Rate And Expected Long-Term Rate Of Return On Plan Assets) (Details) - Pension Benefits $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Increase (decrease) to net pension cost from:
Change in discount rate (increase 25 basis points)	$ (24)
Change in discount rate (decrease 25 basis points)	25
Change in discount rate of return on plan assets (increase of 25 basis points)	(27)
Change in long-term rate of return on plan assets (decrease 25 basis points)	$ 27

Retirement Plans (Asset Allocat

Retirement Plans (Asset Allocation Policy Ranges) (Details)	Dec. 31, 2018
Equity Funds | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	48.00%
Equity Funds | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	68.00%
Fixed Income Funds | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	20.00%
Fixed Income Funds | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	48.00%
Cash and Cash Equivalents | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	0.00%
Cash and Cash Equivalents | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	5.00%
Other Asset Classes | Minimum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	0.00%
Other Asset Classes | Maximum
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range	16.00%

Retirement Plans (Fair Value Of

Retirement Plans (Fair Value Of Plan Assets By Investment Category And The Corresponding Level Within The Fair Value Hierarchy) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Compensation And Retirement Disclosure Line Items
Maximum equity holding percentage of total fair value		1.00%	1.00%
Pension Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		$ 11,532	$ 10,130	$ 8,980
Total plan assets in fair value hierarchy		10,015	9,412
Pension Benefits | Equity Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[1]	86
Pension Benefits | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[1]	101
Pension Benefits | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[1]	420	390
Pension Benefits | Insurance Deposit Agreements
Compensation And Retirement Disclosure Line Items
Total pension plan assets		128	120
Pension Benefits | Hedge Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[1]	910	328
Pension Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		73	48
Pension Benefits | Equity Securities | U.S. Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	732	770
Pension Benefits | Equity Securities | International Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	117	97
Pension Benefits | Equity Securities | Private Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	20	18
Pension Benefits | Fixed Income Securities | Corporate Bonds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[3]	1,600	1,604
Pension Benefits | Fixed Income Securities | Treasury Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		1,410	1,361
Pension Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		5,243	5,018
Pension Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		624	325
Pension Benefits | Comingled Funds | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		68	51
Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		570	541	499
Total plan assets in fair value hierarchy		540	538
Other Post-retirement Benefits | Equity Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[4]	3
Other Post-retirement Benefits | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[4]	3
Other Post-retirement Benefits | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		2	2
Pension plan assets, measured using NAV	[4]	2	2
Other Post-retirement Benefits | Hedge Funds
Compensation And Retirement Disclosure Line Items
Pension plan assets, measured using NAV	[4]	22	1
Other Post-retirement Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		23	18
Other Post-retirement Benefits | Equity Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		80	70
Other Post-retirement Benefits | Fixed Income Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		87	89
Other Post-retirement Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		237	260
Other Post-retirement Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		111	99
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		849	867
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Insurance Deposit Agreements
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Equity Securities | U.S. Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	732	770
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Equity Securities | International Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	117	97
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Equity Securities | Private Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Fixed Income Securities | Corporate Bonds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[3]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Fixed Income Securities | Treasury Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Comingled Funds | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		82	72
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		2	2
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits | Equity Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		80	70
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits | Fixed Income Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Post-retirement Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Other Observable Inputs (Level 2) | Pension Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		8,950	8,356
Significant Other Observable Inputs (Level 2) | Pension Benefits | Insurance Deposit Agreements
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Other Observable Inputs (Level 2) | Pension Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		73	48
Significant Other Observable Inputs (Level 2) | Pension Benefits | Equity Securities | U.S. Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	0	0
Significant Other Observable Inputs (Level 2) | Pension Benefits | Equity Securities | International Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	0	0
Significant Other Observable Inputs (Level 2) | Pension Benefits | Equity Securities | Private Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	0	0
Significant Other Observable Inputs (Level 2) | Pension Benefits | Fixed Income Securities | Corporate Bonds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[3]	1,600	1,604
Significant Other Observable Inputs (Level 2) | Pension Benefits | Fixed Income Securities | Treasury Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		1,410	1,361
Significant Other Observable Inputs (Level 2) | Pension Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		5,243	5,018
Significant Other Observable Inputs (Level 2) | Pension Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		624	325
Significant Other Observable Inputs (Level 2) | Pension Benefits | Comingled Funds | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		458	466
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		23	18
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits | Equity Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits | Fixed Income Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		87	89
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		237	260
Significant Other Observable Inputs (Level 2) | Other Post-retirement Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		111	99
Significant Unobservable Inputs (Level 3)
Compensation And Retirement Disclosure Line Items
Total pension plan assets		216	189	164
Significant Unobservable Inputs (Level 3) | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		68	51	42
Significant Unobservable Inputs (Level 3) | Insurance Deposit Agreements
Compensation And Retirement Disclosure Line Items
Total pension plan assets		128	120	109
Significant Unobservable Inputs (Level 3) | Private Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		20	18	$ 13
Significant Unobservable Inputs (Level 3) | Pension Benefits
Compensation And Retirement Disclosure Line Items
Total pension plan assets		216	189
Significant Unobservable Inputs (Level 3) | Pension Benefits | Insurance Deposit Agreements
Compensation And Retirement Disclosure Line Items
Total pension plan assets		128	120
Significant Unobservable Inputs (Level 3) | Pension Benefits | Cash
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Equity Securities | U.S. Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Equity Securities | International Companies
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Equity Securities | Private Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[2]	20	18
Significant Unobservable Inputs (Level 3) | Pension Benefits | Fixed Income Securities | Corporate Bonds
Compensation And Retirement Disclosure Line Items
Total pension plan assets	[3]	0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Fixed Income Securities | Treasury Securities
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Comingled Funds | Equity Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Comingled Funds | Fixed Income Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		0	0
Significant Unobservable Inputs (Level 3) | Pension Benefits | Comingled Funds | Real Estate Funds
Compensation And Retirement Disclosure Line Items
Total pension plan assets		$ 68	$ 51
[1]	Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets.
[2]	No single equity holding amounted to more than 1% of the total fair value.
[3]	Our corporate bond investments had an average rating of A+.
[4]	Investments measured at fair value using NAV as a practical expedient are not classified in the fair value hierarchy. The fair value amounts presented in this table for these investments are included to permit reconciliation of the fair value hierarchy to the total plan assets.

Retirement Plans (Roll Forward

Retirement Plans (Roll Forward Of Level 3 Pension Assets) (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of assets at beginning of year	$ 189	$ 164
Unrealized gains (losses), net	(1)	9
Realized gains, net	3	2
Purchases, sales, and settlements, net	25	14
Fair value of assets at end of year	216	189
Real Estate Funds
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of assets at beginning of year	51	42
Unrealized gains (losses), net	(1)	4
Realized gains, net	0	0
Purchases, sales, and settlements, net	18	5
Fair value of assets at end of year	68	51
Insurance Deposit Agreements
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of assets at beginning of year	120	109
Unrealized gains (losses), net	0	4
Realized gains, net	3	2
Purchases, sales, and settlements, net	5	5
Fair value of assets at end of year	128	120
Private Equity Investments
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of assets at beginning of year	18	13
Unrealized gains (losses), net	0	1
Realized gains, net	0	0
Purchases, sales, and settlements, net	2	4
Fair value of assets at end of year	$ 20	$ 18

Segment Information (Narrative)

Segment Information (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)Segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | Segment	5
Revenue	$ 36,193	$ 30,973	$ 30,561
Earnings from continuing operations before income tax	$ 4,085	$ 4,077	$ 3,656
Long-lived assets of non-U.S. operations percent of total	3.00%	5.00%	5.00%
International Operations
Segment Reporting Information [Line Items]
Revenue	$ 4,200	$ 3,700	$ 3,700
Earnings from continuing operations before income tax	578	$ 550	$ 530
CSRA
Segment Reporting Information [Line Items]
One-time charges associated with costs to complete acquisition	$ 45

Segment Information (Segment Re

Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue		$ 36,193	$ 30,973	$ 30,561
Operating earnings		4,457	4,236	3,744
Total assets		45,408	35,046	33,172
Capital Expenditures		690	428	392
Depreciation and Amortization		763	441	453
U.S. Government
Segment Reporting Information [Line Items]
Revenue		23,606	19,021	18,676
Aerospace
Segment Reporting Information [Line Items]
Revenue		8,455	8,129	7,815
Aerospace | U.S. Government
Segment Reporting Information [Line Items]
Revenue		334	231	361
Combat Systems
Segment Reporting Information [Line Items]
Revenue		6,241	5,949	5,530
Combat Systems | U.S. Government
Segment Reporting Information [Line Items]
Revenue		3,228	3,084	2,614
Information Technology
Segment Reporting Information [Line Items]
Revenue		8,269	4,410	4,428
Information Technology | U.S. Government
Segment Reporting Information [Line Items]
Revenue		8,025	4,164	4,147
Mission Systems
Segment Reporting Information [Line Items]
Revenue		4,726	4,481	4,716
Mission Systems | U.S. Government
Segment Reporting Information [Line Items]
Revenue		3,774	3,629	3,837
Marine Systems
Segment Reporting Information [Line Items]
Revenue		8,502	8,004	8,072
Marine Systems | U.S. Government
Segment Reporting Information [Line Items]
Revenue		8,245	7,913	7,717
Operating Segments | Aerospace
Segment Reporting Information [Line Items]
Revenue		8,455	8,129	7,815
Operating earnings		1,490	1,577	1,394
Total assets		11,220	10,126	9,792
Capital Expenditures		194	132	125
Depreciation and Amortization		154	147	153
Operating Segments | Aerospace | U.S. Government
Segment Reporting Information [Line Items]
Revenue		334	231	361
Operating Segments | Combat Systems
Segment Reporting Information [Line Items]
Revenue		6,241	5,949	5,530
Operating earnings		962	937	831
Total assets		9,853	9,846	8,885
Capital Expenditures		91	84	71
Depreciation and Amortization		87	86	86
Operating Segments | Combat Systems | U.S. Government
Segment Reporting Information [Line Items]
Revenue		3,228	3,084	2,614
Operating Segments | Information Technology
Segment Reporting Information [Line Items]
Revenue		8,269	4,410	4,428
Operating earnings		608	373	340
Total assets		14,159	3,021	2,778
Capital Expenditures		62	16	10
Depreciation and Amortization		333	32	42
Operating Segments | Information Technology | U.S. Government
Segment Reporting Information [Line Items]
Revenue		8,025	4,164	4,147
Operating Segments | Mission Systems
Segment Reporting Information [Line Items]
Revenue		4,726	4,481	4,716
Operating earnings		659	638	601
Total assets		5,984	5,856	5,667
Capital Expenditures		49	47	87
Depreciation and Amortization		65	60	61
Operating Segments | Mission Systems | U.S. Government
Segment Reporting Information [Line Items]
Revenue		3,774	3,629	3,837
Operating Segments | Marine Systems
Segment Reporting Information [Line Items]
Revenue		8,502	8,004	8,072
Operating earnings		761	685	595
Total assets		3,130	2,906	3,063
Capital Expenditures		243	123	92
Depreciation and Amortization		116	109	105
Operating Segments | Marine Systems | U.S. Government
Segment Reporting Information [Line Items]
Revenue		8,245	7,913	7,717
Corporate
Segment Reporting Information [Line Items]
Revenue		0	0	0
Operating earnings		(23)	26	(17)
Total assets	[1]	1,062	3,291	2,987
Capital Expenditures	[1]	51	26	7
Depreciation and Amortization	[1]	8	7	6
Corporate | U.S. Government
Segment Reporting Information [Line Items]
Revenue		$ 0	$ 0	$ 0
[1]	Corporate identifiable assets are primarily cash and equivalents.

Segment Information (Schedule o

Segment Information (Schedule of Revenues By Geographic Area Based On The Location of Customers) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 36,193	$ 30,973	$ 30,561
North America
Segment Reporting Information [Line Items]
Revenue	29,333	24,434	23,869
North America | United States
Segment Reporting Information [Line Items]
Revenue	28,578	23,519	23,160
North America | Other North America
Segment Reporting Information [Line Items]
Revenue	755	915	709
Europe
Segment Reporting Information [Line Items]
Revenue	2,772	2,558	2,152
Asia Pacific
Segment Reporting Information [Line Items]
Revenue	2,252	2,011	1,650
Africa Middle East
Segment Reporting Information [Line Items]
Revenue	1,565	1,655	2,617
South America
Segment Reporting Information [Line Items]
Revenue	$ 271	$ 315	$ 273

Condensed Consolidating Finan_3

Condensed Consolidating Financial Statements (Narrative) (Details)	12 Months Ended
	Dec. 31, 2018
Consolidating Financial Statements [Abstract]
Percentage of owned subsidiaries guaranteed fixed- and floating-rate notes	100.00%

Condensed Consolidating Finan_4

Condensed Consolidating Financial Statements (Condensed Consolidating Statement Of Earnings) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Consolidating Financial Information [Line Items]
Revenue	$ 36,193	$ 30,973	$ 30,561
Cost of sales	(29,478)	(24,731)	(24,896)
G&A	(2,258)	(2,006)	(1,921)
Operating earnings	4,457	4,236	3,744
Interest, net	(356)	(103)	(91)
Other, net	(16)	(56)	3
Earnings from continuing operations before income tax	4,085	4,077	3,656
Provision for income tax, net	(727)	(1,165)	(977)
Discontinued operations, net of tax	(13)	0	(107)
Equity in net earnings of subsidiaries	0	0	0
Net earnings	3,345	2,912	2,572
Comprehensive income	3,025	3,479	2,468
Consolidating Adjustments
Condensed Consolidating Financial Information [Line Items]
Revenue	0	0	0
Cost of sales	0	0	0
G&A	0	0	0
Operating earnings	0	0	0
Interest, net	0	0	0
Other, net	0	0	0
Earnings from continuing operations before income tax	0	0	0
Provision for income tax, net	0	0	0
Discontinued operations, net of tax	0		0
Equity in net earnings of subsidiaries	(3,672)	(2,899)	(2,676)
Net earnings	(3,672)	(2,899)	(2,676)
Comprehensive income	(3,297)	(3,494)	(2,655)
Parent
Condensed Consolidating Financial Information [Line Items]
Revenue	0	0	0
Cost of sales	67	76	21
G&A	(90)	(48)	(37)
Operating earnings	(23)	28	(16)
Interest, net	(326)	(97)	(91)
Other, net	(81)	(72)	(11)
Earnings from continuing operations before income tax	(430)	(141)	(118)
Provision for income tax, net	116	154	121
Discontinued operations, net of tax	(13)		(107)
Equity in net earnings of subsidiaries	3,672	2,899	2,676
Net earnings	3,345	2,912	2,572
Comprehensive income	3,025	3,479	2,468
Guarantors on a Combined Basis
Condensed Consolidating Financial Information [Line Items]
Revenue	28,132	26,933	26,573
Cost of sales	(22,841)	(21,695)	(21,811)
G&A	(1,638)	(1,643)	(1,568)
Operating earnings	3,653	3,595	3,194
Interest, net	0	1	(2)
Other, net	12	12	5
Earnings from continuing operations before income tax	3,665	3,608	3,197
Provision for income tax, net	(677)	(1,262)	(1,055)
Discontinued operations, net of tax	0		0
Equity in net earnings of subsidiaries	0	0	0
Net earnings	2,988	2,346	2,142
Comprehensive income	2,992	2,336	2,112
Other Subsidiaries on a Combined Basis
Condensed Consolidating Financial Information [Line Items]
Revenue	8,061	4,040	3,988
Cost of sales	(6,704)	(3,112)	(3,106)
G&A	(530)	(315)	(316)
Operating earnings	827	613	566
Interest, net	(30)	(7)	2
Other, net	53	4	9
Earnings from continuing operations before income tax	850	610	577
Provision for income tax, net	(166)	(57)	(43)
Discontinued operations, net of tax	0		0
Equity in net earnings of subsidiaries	0	0	0
Net earnings	684	553	534
Comprehensive income	$ 305	$ 1,158	$ 543

Condensed Consolidating Finan_5

Condensed Consolidating Financial Statements (Condensed Consolidating Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Apr. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and equivalents	$ 963		$ 2,983	$ 2,334	$ 2,785
Accounts receivable	3,759		3,617
Unbilled receivables	6,576		5,240
Inventories	5,977		5,303
Other current assets	914		1,185
Total current assets	18,189		18,328
Noncurrent assets:
PP&E	9,403		8,237
Accumulated depreciation of PP&E	(5,055)		(4,720)
Intangible assets, net	2,585		702
Goodwill	19,594	$ 11,955	11,914	11,445
Other assets	692		585
Net investment in subsidiaries	0		0
Total noncurrent assets	27,219		16,718
Total assets	45,408		35,046	33,172
Current liabilities:
Short-term debt and current portion of long-term debt	973		2
Customer advances and deposits	7,270		6,992
Other current liabilities	6,496		6,105
Total current liabilities	14,739		13,099
Noncurrent liabilities:
Long-term debt	11,444		3,980
Other liabilities	7,493		6,532
Total noncurrent liabilities	18,937		10,512
Total shareholders’ equity	11,732		11,435	10,301	10,440
Total liabilities and shareholders’ equity	45,408		35,046
Consolidating Adjustments
Current assets:
Cash and equivalents	0		0	0	0
Accounts receivable	0		0
Unbilled receivables	0		0
Inventories	0		0
Other current assets	0		0
Total current assets	0		0
Noncurrent assets:
PP&E	0		0
Accumulated depreciation of PP&E	0		0
Intangible assets, net	0		0
Goodwill	0		0
Other assets	0		0
Net investment in subsidiaries	(25,313)		(15,771)
Total noncurrent assets	(25,313)		(15,771)
Total assets	(25,313)		(15,771)
Current liabilities:
Short-term debt and current portion of long-term debt	0		0
Customer advances and deposits	0		0
Other current liabilities	0		0
Total current liabilities	0		0
Noncurrent liabilities:
Long-term debt	0		0
Other liabilities	0		0
Total noncurrent liabilities	0		0
Total shareholders’ equity	(25,313)		(15,771)
Total liabilities and shareholders’ equity	(25,313)		(15,771)
Parent
Current assets:
Cash and equivalents	460		1,930	1,254	1,732
Accounts receivable	0		0
Unbilled receivables	0		0
Inventories	0		0
Other current assets	(45)		351
Total current assets	415		2,281
Noncurrent assets:
PP&E	273		221
Accumulated depreciation of PP&E	(83)		(75)
Intangible assets, net	0		0
Goodwill	0		0
Other assets	195		199
Net investment in subsidiaries	25,313		15,771
Total noncurrent assets	25,698		16,116
Total assets	26,113		18,397
Current liabilities:
Short-term debt and current portion of long-term debt	850		0
Customer advances and deposits	0		0
Other current liabilities	552		561
Total current liabilities	1,402		561
Noncurrent liabilities:
Long-term debt	11,398		3,950
Other liabilities	1,581		2,451
Total noncurrent liabilities	12,979		6,401
Total shareholders’ equity	11,732		11,435
Total liabilities and shareholders’ equity	26,113		18,397
Guarantors on a Combined Basis
Current assets:
Cash and equivalents	0		0	0	0
Accounts receivable	1,171		1,259
Unbilled receivables	2,758		2,547
Inventories	5,855		5,216
Other current assets	441		461
Total current assets	10,225		9,483
Noncurrent assets:
PP&E	7,197		6,779
Accumulated depreciation of PP&E	(4,075)		(3,869)
Intangible assets, net	251		287
Goodwill	8,031		8,320
Other assets	258		232
Net investment in subsidiaries	0		0
Total noncurrent assets	11,662		11,749
Total assets	21,887		21,232
Current liabilities:
Short-term debt and current portion of long-term debt	0		1
Customer advances and deposits	4,541		4,180
Other current liabilities	3,944		3,758
Total current liabilities	8,485		7,939
Noncurrent liabilities:
Long-term debt	39		21
Other liabilities	4,073		3,473
Total noncurrent liabilities	4,112		3,494
Total shareholders’ equity	9,290		9,799
Total liabilities and shareholders’ equity	21,887		21,232
Other Subsidiaries on a Combined Basis
Current assets:
Cash and equivalents	503		1,053	$ 1,080	$ 1,053
Accounts receivable	2,588		2,358
Unbilled receivables	3,818		2,693
Inventories	122		87
Other current assets	518		373
Total current assets	7,549		6,564
Noncurrent assets:
PP&E	1,933		1,237
Accumulated depreciation of PP&E	(897)		(776)
Intangible assets, net	2,334		415
Goodwill	11,563		3,594
Other assets	239		154
Net investment in subsidiaries	0		0
Total noncurrent assets	15,172		4,624
Total assets	22,721		11,188
Current liabilities:
Short-term debt and current portion of long-term debt	123		1
Customer advances and deposits	2,729		2,812
Other current liabilities	2,000		1,786
Total current liabilities	4,852		4,599
Noncurrent liabilities:
Long-term debt	7		9
Other liabilities	1,839		608
Total noncurrent liabilities	1,846		617
Total shareholders’ equity	16,023		5,972
Total liabilities and shareholders’ equity	$ 22,721		$ 11,188

Condensed Consolidating Finan_6

Condensed Consolidating Financial Statements (Condensed Consolidating Statement Of Cash Flows) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Consolidating Financial Information [Line Items]
Net cash provided by operating activities	[1]	$ 3,148	$ 3,876	$ 2,163
Cash flows from investing activities:
Business acquisitions, net of cash acquired		(10,099)	(399)	(58)
Capital expenditures		(690)	(428)	(392)
Proceeds from sales of assets		562	50	9
Other, net		(7)	39	1
Net cash used by investing activities		(10,234)	(788)	(391)
Cash flows from financing activities:
Proceeds from notes		6,461	985	992
Purchases of common stock		(1,769)	(1,558)	(1,996)
Dividends paid		(1,075)	(986)	(911)
Proceeds from commercial paper, net		851	0	0
Repayment of CSRA accounts receivable purchase agreement		(450)	0	0
Repayments of fixed-rate notes		0	(900)	(500)
Proceeds from stock option exercises		136	163	292
Other, net		68	60	(46)
Net cash provided (used) by financing activities		5,086	(2,399)	(2,169)
Net cash used by discontinued operations		(20)	(40)	(54)
Cash sweep/funding by parent		0	0	0
Net (decrease) increase in cash and equivalents		(2,020)	649	(451)
Cash and equivalents at beginning of year		2,983	2,334	2,785
Cash and equivalents at end of year		963	2,983	2,334
Consolidating Adjustments
Condensed Consolidating Financial Information [Line Items]
Net cash provided by operating activities	[1]	0	0	0
Cash flows from investing activities:
Business acquisitions, net of cash acquired		0	0
Capital expenditures		0	0	0
Proceeds from sales of assets		0
Other, net		0	0	0
Net cash used by investing activities		0	0	0
Cash flows from financing activities:
Proceeds from notes		0	0	0
Purchases of common stock		0	0	0
Dividends paid		0	0	0
Proceeds from commercial paper, net		0
Repayment of CSRA accounts receivable purchase agreement		0
Repayments of fixed-rate notes			0	0
Proceeds from stock option exercises				0
Other, net		0	0	0
Net cash provided (used) by financing activities		0	0	0
Net cash used by discontinued operations		0	0	0
Cash sweep/funding by parent		0	0	0
Net (decrease) increase in cash and equivalents		0	0	0
Cash and equivalents at beginning of year		0	0	0
Cash and equivalents at end of year		0	0	0
Parent
Condensed Consolidating Financial Information [Line Items]
Net cash provided by operating activities	[1]	(579)	312	217
Cash flows from investing activities:
Business acquisitions, net of cash acquired		(9,749)	0
Capital expenditures		(51)	(26)	(8)
Proceeds from sales of assets		90
Other, net		4	10	7
Net cash used by investing activities		(9,706)	(16)	(1)
Cash flows from financing activities:
Proceeds from notes		6,461	985	992
Purchases of common stock		(1,769)	(1,558)	(1,996)
Dividends paid		(1,075)	(986)	(911)
Proceeds from commercial paper, net		851
Repayment of CSRA accounts receivable purchase agreement		0
Repayments of fixed-rate notes			(900)	(500)
Proceeds from stock option exercises				292
Other, net		2	63	(45)
Net cash provided (used) by financing activities		5,470	(2,396)	(2,168)
Net cash used by discontinued operations		(20)	(40)	(54)
Cash sweep/funding by parent		3,365	2,816	1,528
Net (decrease) increase in cash and equivalents		(1,470)	676	(478)
Cash and equivalents at beginning of year		1,930	1,254	1,732
Cash and equivalents at end of year		460	1,930	1,254
Guarantors on a Combined Basis
Condensed Consolidating Financial Information [Line Items]
Net cash provided by operating activities	[1]	2,954	2,371	1,881
Cash flows from investing activities:
Business acquisitions, net of cash acquired		(74)	(350)
Capital expenditures		(513)	(330)	(336)
Proceeds from sales of assets		472
Other, net		(12)	31	32
Net cash used by investing activities		(127)	(649)	(304)
Cash flows from financing activities:
Proceeds from notes		0	0	0
Purchases of common stock		0	0	0
Dividends paid		0	0	0
Proceeds from commercial paper, net		0
Repayment of CSRA accounts receivable purchase agreement		0
Repayments of fixed-rate notes			0	0
Proceeds from stock option exercises				0
Other, net		35	(3)	(1)
Net cash provided (used) by financing activities		35	(3)	(1)
Net cash used by discontinued operations		0	0	0
Cash sweep/funding by parent		(2,862)	(1,719)	(1,576)
Net (decrease) increase in cash and equivalents		0	0	0
Cash and equivalents at beginning of year		0	0	0
Cash and equivalents at end of year		0	0	0
Other Subsidiaries on a Combined Basis
Condensed Consolidating Financial Information [Line Items]
Net cash provided by operating activities	[1]	773	1,193	65
Cash flows from investing activities:
Business acquisitions, net of cash acquired		(276)	(49)
Capital expenditures		(126)	(72)	(48)
Proceeds from sales of assets		0
Other, net		1	(2)	(38)
Net cash used by investing activities		(401)	(123)	(86)
Cash flows from financing activities:
Proceeds from notes		0	0	0
Purchases of common stock		0	0	0
Dividends paid		0	0	0
Proceeds from commercial paper, net		0
Repayment of CSRA accounts receivable purchase agreement		(450)
Repayments of fixed-rate notes			0	0
Proceeds from stock option exercises				0
Other, net		31	0	0
Net cash provided (used) by financing activities		(419)	0	0
Net cash used by discontinued operations		0	0	0
Cash sweep/funding by parent		(503)	(1,097)	48
Net (decrease) increase in cash and equivalents		(550)	(27)	27
Cash and equivalents at beginning of year		1,053	1,080	1,053
Cash and equivalents at end of year		503	1,053	1,080
LIBOR
Cash flows from financing activities:
Proceeds from notes		1,000	$ 0	$ 0
LIBOR | Consolidating Adjustments
Cash flows from financing activities:
Proceeds from notes		0
LIBOR | Parent
Cash flows from financing activities:
Proceeds from notes		1,000
LIBOR | Guarantors on a Combined Basis
Cash flows from financing activities:
Proceeds from notes		0
LIBOR | Other Subsidiaries on a Combined Basis
Cash flows from financing activities:
Proceeds from notes		$ 0
[1]	* Continuing operations only.