Goodwill and Other Purchased Intangible Assets (Details 1) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill (Table Amounts)
Beginning balance	$ 12,450	$ 12,460
Businesses sold and other	5	(10)
Ending balance	12,455	12,450
Aerospace Systems
Goodwill (Table Amounts)
Beginning balance	3,742	3,742
Businesses sold and other	0	0
Ending balance	3,742	3,742
Mission Systems
Goodwill (Table Amounts)
Beginning balance	6,694	6,704
Businesses sold and other	2	(10)
Ending balance	6,696	6,694
Technology Services
Goodwill (Table Amounts)
Beginning balance	2,014	2,014
Businesses sold and other	3	0
Ending balance	$ 2,017	$ 2,014