Segment Information (Unaudited) (Details 1) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Sales	$ 8,085	$ 6,569	$ 21,939	$ 19,452
Operating income	1,178	837	2,855	2,572
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	979	756	2,520	2,256
Operating Segments [Member] | Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Sales	3,282	3,125	9,899	9,112
Operating income	376	344	1,074	987
Operating Segments [Member] | Innovation Systems [Member]
Segment Reporting Information [Line Items]
Sales	1,415	0	1,815	0
Operating income	161	0	200	0
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,911	2,836	8,668	8,495
Operating income	399	359	1,122	1,102
Operating Segments [Member] | Technology Services [Member]
Segment Reporting Information [Line Items]
Sales	1,040	1,183	3,232	3,535
Operating income	111	124	328	378
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales	563	575	1,675	1,690
Operating income	68	71	204	211
Net FAS (service)/CAS pension adjustment [Member]
Segment Reporting Information [Line Items]
Operating income	176	170	440	478
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	24	(88)	(102)	(159)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	$ (1)	$ (1)	$ (3)	$ (3)