Segment Information (Unaudited) (Details 1) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Sales	$ 7,119	$ 6,473	$ 13,854	$ 12,883
Operating income	823	873	1,677	1,735
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	779	759	1,541	1,500
Operating Segments [Member] | Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Sales	3,337	3,003	6,617	5,987
Operating income	357	320	698	643
Operating Segments [Member] | Innovation Systems [Member]
Segment Reporting Information [Line Items]
Sales	400	0	400	0
Operating income	39	0	39	0
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,874	2,859	5,757	5,659
Operating income	352	384	723	743
Operating Segments [Member] | Technology Services [Member]
Segment Reporting Information [Line Items]
Sales	1,048	1,162	2,192	2,352
Operating income	95	125	217	254
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales	540	551	1,112	1,115
Operating income	64	70	136	140
Net FAS (service)/CAS pension adjustment [Member]
Segment Reporting Information [Line Items]
Operating income	137	154	264	308
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	(92)	(39)	(126)	(71)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	$ (1)	$ (1)	$ (2)	$ (2)