Acquisitions, Divestitures, Goodwill and Intangible Assets - Changes In Amount Of Goodwill (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Goodwill [Roll Forward]
Goodwill impairment	$ 0		$ 0		$ 1,994
Acquisitions	127	[1]	2	[1]
Other	(328)		(73)
Goodwill, end of period	11,731		11,932		12,003
Aerospace
Goodwill [Roll Forward]
Acquisitions	0	[1]	0	[1]
Other	(186)		44
Goodwill, end of period	2,555		2,741		2,697
Combat Systems
Goodwill [Roll Forward]
Acquisitions	0	[1]	2	[1]
Other	(99)		(69)
Goodwill, end of period	2,750		2,849		2,916
Marine Systems
Goodwill [Roll Forward]
Acquisitions	0	[1]	(1)	[1]
Other	0		0
Goodwill, end of period	289		289		290
Information Systems and Technology
Goodwill [Roll Forward]
Goodwill, beginning of period			1,994
Goodwill impairment					2,000
Acquisitions	127	[1]	1	[1]
Other	(43)		(48)
Goodwill, end of period	$ 6,137		$ 6,053		$ 6,100

[1] Includes adjustments during the purchase price allocation period