Segment Information (Unaudited) (Details 1) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) segment	Sep. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Sales	$ 6,155	$ 5,979	$ 18,111	$ 17,832
Operating income	826	794	2,362	2,387
Benefit from claimed state refund	30
Benefit from overhead claim recoveries	25
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	731	726	2,163	2,203
Operating Segments [Member] | Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,782	2,544	7,956	7,540
Operating income	311	298	909	929
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,698	2,723	8,081	8,062
Operating income	351	355	1,055	1,047
Operating Segments [Member] | Technology Services [Member]
Segment Reporting Information [Line Items]
Sales	1,190	1,193	3,617	3,698
Operating income	130	128	387	389
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales	515	481	1,543	1,468
Operating income	61	55	188	162
Net FAS/CAS pension adjustment Income (Expense) [Member]
Segment Reporting Information [Line Items]
Operating income	91	97	234	261
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	5	(29)	(31)	(76)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	$ (1)	$ 0	$ (4)	$ (1)