Acquisitions, Divestitures and Goodwill (Rollforward of Goodwill by Segments) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning balance	$ 14,864,000,000	$ 14,871,000,000
Acquisitions and divestitures	19,000,000	(3,000,000)	$ 77,000,000
Effect of foreign exchange rates and other	(1,000,000)	(4,000,000)
Ending Balance	14,882,000,000	14,864,000,000	14,871,000,000
Integrated Defense Systems
Goodwill [Roll Forward]
Beginning balance	1,704,000,000	1,706,000,000
Acquisitions and divestitures	0	0
Effect of foreign exchange rates and other	(1,000,000)	(2,000,000)
Ending Balance	1,703,000,000	1,704,000,000	1,706,000,000
Intelligence, Information and Services
Goodwill [Roll Forward]
Beginning balance	2,965,000,000	2,967,000,000
Acquisitions and divestitures	19,000,000	0
Effect of foreign exchange rates and other	0	(2,000,000)
Ending Balance	2,984,000,000	2,965,000,000	2,967,000,000
Missile Systems
Goodwill [Roll Forward]
Beginning balance	4,154,000,000	4,154,000,000
Acquisitions and divestitures	0	0
Effect of foreign exchange rates and other	0	0
Ending Balance	4,154,000,000	4,154,000,000	4,154,000,000
Space and Airborne Systems
Goodwill [Roll Forward]
Beginning balance	4,103,000,000	4,106,000,000
Acquisitions and divestitures	0	(3,000,000)
Effect of foreign exchange rates and other	0	0
Ending Balance	4,103,000,000	4,103,000,000	4,106,000,000
Forcepoint
Goodwill [Roll Forward]
Beginning balance	1,938,000,000	1,938,000,000
Acquisitions and divestitures	0	0
Effect of foreign exchange rates and other	0	0
Ending Balance	$ 1,938,000,000	$ 1,938,000,000	$ 1,938,000,000