Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Remeasurement of deferred tax asset		$ 1,900
Deferred tax asset, increase (decrease), amount	$ 1,900
Effect of change on earnings per share (in dollars per share)		$ 6.80	$ 6.69
Total net state income tax expense			$ 103	$ 112	$ 106
U.S. manufacturing deduction benefit (insignificant)			7	117	123
Recognized tax benefit for the impact of the tax credit			115	107	70
Net deferred tax expense (benefit)			1,613	(231)	(473)
Unrecognized tax benefits	0	$ 0	0	0
Deemed repatriated earnings	$ 435	$ 435	435
Tax cuts and jobs act Of 2017, incomplete accounting, transition tax for accumulated foreign earnings, income tax expense (benefit)			43
Undistributed earnings of foreign subsidiaries not taxed to U.S. income taxes and foreign withholding taxes				386	310
Federal and foreign income tax payments made, net of refunds received			$ 1,100	1,300	1,800
Internal Revenue Service (IRS) | Earliest Tax Year
Income Taxes [Line Items]
Tax years subject to examination			2015
Internal Revenue Service (IRS) | Tax Year 2016
Income Taxes [Line Items]
Tax years subject to examination			2016
Internal Revenue Service (IRS) | Tax Year 2017
Income Taxes [Line Items]
Tax years subject to examination			2017
Lockheed Martin Commercial Flight Training
Income Taxes [Line Items]
Asset impairment charges					90
Net deferred tax expense (benefit)					$ (80)
Tax benefit reduced the effective income tax rate					1.20%
Unaudited Supplemental Pro Forma Financial Information
Income Taxes [Line Items]
Tax cuts and jobs act Of 2017, incomplete accounting, transition tax for accumulated foreign earnings, income tax expense (benefit)				64	$ 49
Accounting Standards Update 2016-09 | Restatement Adjustment | Adjustments for New Accounting Principle, Early Adoption
Income Taxes [Line Items]
Excess income tax benefit from share-based compensation, operating activities			$ 106	$ 152