Information on Business Segments - Summary of Financial Information for Each Business Segment (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	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, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 24, 2016
Net sales
Net sales	$ 15,137	$ 12,169	$ 12,685	$ 11,057	$ 13,752	$ 11,551	$ 11,577	$ 10,368	$ 51,048	$ 47,248	$ 40,536
Operating profit
Operating profit	$ 1,859	$ 1,428	$ 1,485	1,149	$ 1,428	$ 1,588	$ 1,375	$ 1,158	5,921	5,549	4,712
FAS/CAS pension adjustment									876	902	400
Severance charges									0	80	82
Stock-based compensation									158	149	133
Depreciation and amortization									1,195	1,167	945
Capital expenditures									1,177	1,063	939
Gain on property sale									198	0	0
Equity method investee impairment											90
Net deferred tax expense (benefit)									1,613	(231)	(473)
Lockheed Martin Commercial Flight Training
Operating profit
Net deferred tax expense (benefit)											(80)
AWE Management Limited
Operating profit
Ownership interest percentage owned immediately before acquisition												33.00%
Ownership interest percentage owned subsequent acquisition												51.00%
Sikorsky Aircraft Corporation
Operating profit
Non-recoverable transaction costs											38
Information Systems & Global Solutions
Operating profit
Depreciation and amortization										48	81
Capital expenditures										9	31
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Lockheed Martin Commercial Flight Training
Operating profit
Net deferred tax expense (benefit)											(80)
Reduction in net earnings											10
Net Earnings From Continuing Operations | AWE Management Limited
Operating profit
Gain (loss) associated with obtaining control of AWE										$ 104
Increase in net earnings from continuing operations (in dollars per share)										$ 0.34
Continuing Operations
Operating profit
Capital expenditures									1,177	$ 1,054	908
Aeronautics
Net sales
Net sales									20,148	17,769	15,570
Missiles and Fire Control
Net sales
Net sales									7,212	6,608	6,770
Rotary and Mission Systems
Net sales
Net sales									14,215	13,462	9,091
Space
Net sales
Net sales									9,473	9,409	9,105
Operating Segments
Operating profit
Operating profit									5,115	5,100	4,978
Depreciation and amortization									1,123	1,092	847
Capital expenditures									1,014	979	848
Operating Segments | Aeronautics
Operating profit
Operating profit									2,164	1,887	1,681
Depreciation and amortization									311	299	317
Capital expenditures									371	358	387
Operating Segments | Missiles and Fire Control
Operating profit
Operating profit									1,053	1,018	1,282
Depreciation and amortization									99	105	99
Capital expenditures									156	167	120
Operating Segments | Rotary and Mission Systems
Operating profit
Operating profit									905	906	844
Depreciation and amortization									468	476	211
Capital expenditures									308	271	169
Operating Segments | Space
Operating profit
Operating profit									993	1,289	1,171
Depreciation and amortization									245	212	220
Capital expenditures									179	183	172
Operating Segments | Space | AWE Management Limited
Operating profit
Gain (loss) associated with obtaining control of AWE										127
Segment Reconciling Items
Operating profit
Net periodic benefit cost									(1,372)	(1,019)	(1,127)
Less: CAS pension cost									2,248	1,921	1,527
FAS/CAS pension adjustment									876	902	400
Severance charges									0	(80)	(82)
Stock-based compensation									(158)	(149)	(133)
Other, net									88	(224)	(451)
Total unallocated items									806	449	(266)
Intersegment sales
Net sales
Net sales									2,608	2,368	2,096
Intersegment sales | Aeronautics
Net sales
Net sales									122	137	102
Intersegment sales | Missiles and Fire Control
Net sales
Net sales									366	305	315
Intersegment sales | Rotary and Mission Systems
Net sales
Net sales									2,009	1,816	1,533
Intersegment sales | Space
Net sales
Net sales									111	110	146
Corporate activities
Operating profit
Depreciation and amortization									72	75	98
Capital expenditures									163	75	$ 60
Corporate activities | AWE Management Limited
Operating profit
Gain (loss) associated with obtaining control of AWE										$ (23)
Land
Operating profit
Gain on property sale									198
AMMROC
Operating profit
Equity method investee impairment				$ 64					$ 64