Acquisitions and Divestitures, Goodwill and Intangible Assets - Changes In Amount of Goodwill (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, beginning of period	[1]	$ 19,594
Acquisitions	[2]	80
Other	[3]	(6)
Goodwill, end of period	[1]	19,668
Aerospace
Goodwill [Roll Forward]
Goodwill, beginning of period	[1]	2,813
Acquisitions	[2]	3
Other	[3]	(20)
Goodwill, end of period	[1]	2,796
Combat Systems
Goodwill [Roll Forward]
Goodwill, beginning of period	[1]	2,633
Acquisitions	[2]	(1)
Other	[3]	9
Goodwill, end of period	[1]	2,641
Information Technology
Goodwill [Roll Forward]
Goodwill, beginning of period	[1]	9,622
Acquisitions	[2]	72
Other	[3]	1
Goodwill, end of period	[1]	9,695
Accumulated impairment loss		536	$ 536
Mission Systems
Goodwill [Roll Forward]
Goodwill, beginning of period	[1]	4,229
Acquisitions	[2]	6
Other	[3]	4
Goodwill, end of period	[1]	4,239
Accumulated impairment loss		1,300	$ 1,300
Marine Systems
Goodwill [Roll Forward]
Goodwill, beginning of period	[1]	297
Acquisitions	[2]	0
Other	[3]	0
Goodwill, end of period	[1]	$ 297

[1] Goodwill in the Information Technology and Mission Systems reporting units is net of $536 and $1.3 billion of accumulated impairment losses, respectively.

[2] Includes adjustments during the purchase price allocation period.

[3] Consists primarily of adjustments for foreign currency translation