Segment Information (Unaudited) (Details 1) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) segment	Sep. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Sales	$ 6,527	$ 6,155	$ 19,169	$ 18,111
Operating income	845	826	2,532	2,362
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	759	731	2,238	2,163
Operating Segments [Member] | Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Sales	3,082	2,782	8,950	7,956
Operating income	334	311	961	909
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,837	2,698	8,357	8,081
Operating income	363	351	1,090	1,055
Operating Segments [Member] | Technology Services [Member]
Segment Reporting Information [Line Items]
Sales	1,183	1,190	3,552	3,617
Operating income	133	130	398	387
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales	575	515	1,690	1,543
Operating income	71	61	211	188
Net FAS/CAS pension adjustment Income (Expense) [Member]
Segment Reporting Information [Line Items]
Operating income	172	91	445	234
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	(85)	5	(148)	(31)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	$ (1)	$ (1)	$ (3)	$ (4)