Acquisitions and Divestitures - Additional Information (Detail) - USD ($)				2 Months Ended	3 Months Ended									8 Months Ended	12 Months Ended			16 Months Ended
	Aug. 24, 2016	Aug. 16, 2016	Nov. 06, 2015	Dec. 31, 2015	Dec. 31, 2017	Sep. 24, 2017	Jun. 25, 2017	Mar. 26, 2017	Dec. 31, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 31, 2015	Aug. 23, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Acquisitions And Divestitures [Line Items]
Acquisitions of businesses and investments in affiliates															$ 0	$ 0	$ 9,003,000,000
Proceeds from borrowings under revolving credit facilities															0	0	6,000,000,000
Proceeds from issuance of fixed interest-rate long-term notes															0	0	9,101,000,000
Aggregate amount of goodwill arising from acquisitions				$ 10,695,000,000	$ 10,807,000,000				$ 10,764,000,000				$ 10,695,000,000		10,807,000,000	10,764,000,000	10,695,000,000	$ 10,807,000,000
Amortization of intangible assets															312,000,000	284,000,000	68,000,000
Income tax charge related to historic earnings of foreign subsidiaries				310,000,000					386,000,000				310,000,000			386,000,000	310,000,000
One-time special cash payment received from Abacus		$ 1,800,000,000													0	1,800,000,000	0
Net gain on divestiture of business segment															73,000,000	1,242,000,000	0
Fair value of shares of common stock tendered and retired																2,497,000,000
Severance charges															0	99,000,000	102,000,000
Net deferred tax expense (benefit)															1,613,000,000	(231,000,000)	(473,000,000)
Net earnings from discontinued operations					73,000,000	$ 0	$ 0	$ 0	29,000,000	$ 1,306,000,000	$ 122,000,000	$ 92,000,000			73,000,000	1,549,000,000	479,000,000
Space
Acquisitions And Divestitures [Line Items]
Aggregate amount of goodwill arising from acquisitions				1,588,000,000	1,587,000,000				1,585,000,000				1,588,000,000		1,587,000,000	1,585,000,000	1,588,000,000	1,587,000,000
November 2015 Notes
Acquisitions And Divestitures [Line Items]
Amount of issued debt				7,000,000,000.0									7,000,000,000.0				7,000,000,000.0
Abacus | Term Loan Facilities
Acquisitions And Divestitures [Line Items]
Amount of issued debt		$ 1,840,000,000
Information Systems & Global Solutions
Acquisitions And Divestitures [Line Items]
Percentage of reduction in common stock outstanding		3.00%
Net gain on divestiture of business segment		$ 1,300,000,000			73,000,000					1,200,000,000						1,200,000,000
Fair value of shares of common stock tendered and retired		2,500,000,000
Net book value		3,000,000,000
Other adjustments		$ 100,000,000
Information Systems & Global Solutions | Lockheed Martin
Acquisitions And Divestitures [Line Items]
Number of common stock exchanged (in shares)		9,369,694
Information Systems & Global Solutions | Continuing Operations
Acquisitions And Divestitures [Line Items]
Pension costs																54,000,000	71,000,000
Information Systems & Global Solutions | Discontinued Operations
Acquisitions And Divestitures [Line Items]
Severance charges																19,000,000	20,000,000
Information Systems & Global Solutions | Restatement Adjustment
Acquisitions And Divestitures [Line Items]
Corporate overhead costs																(82,000,000)	(165,000,000)
Information Systems & Global Solutions | Discontinued Operations, Disposed of by Sale
Acquisitions And Divestitures [Line Items]
Net gain on divestiture of business segment															73,000,000
Net earnings from discontinued operations																1,549,000,000	479,000,000
Lockheed Martin Commercial Flight Training | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Acquisitions And Divestitures [Line Items]
Asset impairment charges																	90,000,000
Net deferred tax expense (benefit)																	(80,000,000)
Reduction in net earnings																	10,000,000
Sikorsky Aircraft Corporation
Acquisitions And Divestitures [Line Items]
Acquisitions of businesses and investments in affiliates			$ 9,000,000,000
Cash on hand			2,000,000,000
Proceeds from issuance of Commercial Paper			$ 1,000,000,000
Repayment of commercial paper													1,000,000,000
Acquired intangible assets, weighted average period of amortization			15 years
Customer contractual obligations			$ 507,000,000
Sales related to customer contractual obligations, to date					225,000,000										225,000,000			225,000,000
Customer contractual obligations due in 2018					100,000,000										100,000,000			100,000,000
Customer contractual obligations due in 2019					55,000,000										55,000,000			55,000,000
Customer contractual obligations due in 2020					55,000,000										55,000,000			55,000,000
Customer contractual obligations due in 2021					55,000,000										55,000,000			55,000,000
Customer contractual obligations due in 2022					5,000,000										5,000,000			5,000,000
Customer contractual obligations due after 2022					$ 12,000,000										$ 12,000,000			$ 12,000,000
Aggregate amount of goodwill arising from acquisitions			2,842,000,000
Net sales				400,000,000
Net earnings (loss)				(45,000,000)
Non-recoverable transaction costs																	38,000,000
Net liabilities			2,989,000,000
Sikorsky Aircraft Corporation | 364 Day Revolving Credit Facility And Five Year Revolving Credit Facility
Acquisitions And Divestitures [Line Items]
Proceeds from borrowings under revolving credit facilities			$ 6,000,000,000
Debt Instrument, term															364 days
Sikorsky Aircraft Corporation | November 2015 Notes
Acquisitions And Divestitures [Line Items]
Proceeds from issuance of fixed interest-rate long-term notes													7,000,000,000
Costs associated with issuance of fixed interest-rate long-term notes				48,000,000
Sikorsky Aircraft Corporation | Pro Forma Adjustment
Acquisitions And Divestitures [Line Items]
Amortization of intangible assets																	125,000,000
Interest expense, debt																	40,000,000
Pension curtailment loss																	72,000,000
Income tax charge related to historic earnings of foreign subsidiaries				$ 58,000,000									$ 58,000,000				58,000,000
Sikorsky Aircraft Corporation | Unaudited Supplemental Pro Forma Financial Information
Acquisitions And Divestitures [Line Items]
Increase in interest expense, net of tax																	$ 110,000,000
AWE Management Limited
Acquisitions And Divestitures [Line Items]
Ownership interest percentage owned immediately before acquisition	33.00%
Net sales									307,000,000	103,000,000
Net earnings (loss)									$ 3,000,000	$ 104,000,000
Ownership interest percentage owned subsequent acquisition	51.00%
Net liabilities	$ 32,000,000
Business combination, acquisition of less than 100 percent, noncontrolling interest, fair value	107,000,000
AWE Management Limited | Net Sales | Segment Concentration Risk | Space
Acquisitions And Divestitures [Line Items]
Concentration percentage															100.00%			100.00%
AWE Management Limited | Net Sales | Equity Method Investment Risk | Space
Acquisitions And Divestitures [Line Items]
Concentration percentage															0.00%
AWE Management Limited | Operating profit | Segment Concentration Risk | Space
Acquisitions And Divestitures [Line Items]
Concentration percentage															51.00%			51.00%
AWE Management Limited | Net Earnings | Equity Method Investment Risk | Space
Acquisitions And Divestitures [Line Items]
Concentration percentage														33.00%
AWE Management Limited | Net Earnings From Continuing Operations
Acquisitions And Divestitures [Line Items]
Gain (loss) associated with obtaining control of AWE																104,000,000
AWE Management Limited | Customer relationships
Acquisitions And Divestitures [Line Items]
Intangible assets	$ 243,000,000
Acquired finite-lived intangible assets are amortized	8 years
Pre-tax gain recognized in operating results of Space System business segment | AWE Management Limited | Space
Acquisitions And Divestitures [Line Items]
Gain (loss) associated with obtaining control of AWE																127,000,000
Deferred tax liabilities at corporate office | AWE Management Limited
Acquisitions And Divestitures [Line Items]
Gain (loss) associated with obtaining control of AWE																$ (23,000,000)