Goodwill and Acquired Intangibles - Changes in the Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 10,604	$ 10,769
Distributed Energy Solutions divestiture		(175)
Acquisitions	189
Other	13	10
Goodwill, ending balance	10,806	10,604
Aeronautics
Goodwill [Roll Forward]
Goodwill, beginning balance	171	171
Distributed Energy Solutions divestiture		0
Acquisitions	16
Other	0	0
Goodwill, ending balance	187	171
MFC
Goodwill [Roll Forward]
Goodwill, beginning balance	2,089	2,262
Distributed Energy Solutions divestiture		(175)
Acquisitions	0
Other	2	2
Goodwill, ending balance	2,091	2,089
RMS
Goodwill [Roll Forward]
Goodwill, beginning balance	6,758	6,751
Distributed Energy Solutions divestiture		0
Acquisitions	0
Other	10	7
Goodwill, ending balance	6,768	6,758
Space
Goodwill [Roll Forward]
Goodwill, beginning balance	1,586	1,585
Distributed Energy Solutions divestiture		0
Acquisitions	173
Other	1	1
Goodwill, ending balance	$ 1,760	$ 1,586