Segment Information (Unaudited) (Details 1) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Sales	$ 6,375	$ 6,000	$ 12,642	$ 11,956
Operating income	855	797	1,687	1,536
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	753	731	1,479	1,432
Operating Segments [Member] | Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,970	2,600	5,868	5,174
Operating income	315	312	627	598
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,781	2,690	5,520	5,383
Operating income	374	351	727	704
Operating Segments [Member] | Technology Services [Member]
Segment Reporting Information [Line Items]
Sales	1,175	1,213	2,369	2,427
Operating income	134	131	265	257
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales	551	503	1,115	1,028
Operating income	70	63	140	127
Net FAS/CAS pension adjustment Income (Expense) [Member]
Segment Reporting Information [Line Items]
Operating income	137	69	273	143
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	(34)	(3)	(63)	(36)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	$ (1)	$ 0	$ (2)	$ (3)