Segment Information (Unaudited) (Details 1) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Sales	$ 8,475	$ 8,085	$ 25,120	$ 21,939
Operating income	951	1,172	2,833	2,837
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	940	979	2,885	2,520
Operating Segments [Member] | Aerospace Systems [Member]
Segment Reporting Information [Line Items]
Sales	3,458	3,282	10,344	9,899
Operating income	324	376	1,067	1,074
Operating Segments [Member] | Innovation Systems [Member]
Segment Reporting Information [Line Items]
Sales	1,584	1,415	4,520	1,815
Operating income	164	161	500	200
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	3,029	2,911	9,043	8,668
Operating income	398	399	1,189	1,122
Operating Segments [Member] | Technology Services [Member]
Segment Reporting Information [Line Items]
Sales	1,067	1,040	3,088	3,232
Operating income	136	111	351	328
Intersegment sales
Segment Reporting Information [Line Items]
Sales	(663)	(563)	(1,875)	(1,675)
Operating income	(82)	(68)	(222)	(204)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net FAS (service)/ CAS pension adjustment	131	176	346	440
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	$ (120)	$ 17	$ (398)	$ (123)