Segment Information (Details 2) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Intersegment sales and operating income (Table Amounts) [Abstract]
Total sales	$ 6,397	$ 6,155	$ 6,000	$ 5,956	$ 5,694	$ 5,979	$ 5,896	$ 5,957	$ 24,508	$ 23,526	$ 23,979
Operating income	$ 831	$ 826	$ 797	$ 739	$ 689	$ 794	$ 813	$ 780	3,193	3,076	3,196
Intersegment Eliminations [Member]
Intersegment sales and operating income (Table Amounts) [Abstract]
Total sales									2,073	1,907	1,834
Operating income									258	209	204
Intersegment Eliminations [Member] | Aerospace Systems
Intersegment sales and operating income (Table Amounts) [Abstract]
Total sales									239	221	166
Operating income									28	27	21
Intersegment Eliminations [Member] | Mission Systems
Intersegment sales and operating income (Table Amounts) [Abstract]
Total sales									875	781	842
Operating income									136	97	115
Intersegment Eliminations [Member] | Technology Services
Intersegment sales and operating income (Table Amounts) [Abstract]
Total sales									959	905	826
Operating income									$ 94	$ 85	$ 68