Segment Information (Unaudited) Reconciliation to Consolidated Operating Income (Details 1) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			4
Sales	$ 9,083	$ 8,475	$ 26,587	$ 25,120
Operating income	985	951	2,913	2,833
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	1,049	955	3,047	2,926
Operating Segments [Member] | Aeronautics Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,914	2,770	8,682	8,309
Operating income	294	269	867	879
Operating Segments [Member] | Defense Systems [Member]
Segment Reporting Information [Line Items]
Sales	1,859	1,931	5,626	5,615
Operating income	217	201	632	617
Operating Segments [Member] | Mission Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,551	2,310	7,344	6,924
Operating income	370	351	1,070	1,012
Operating Segments [Member] | Space Systems [Member]
Segment Reporting Information [Line Items]
Sales	2,198	1,885	6,194	5,474
Operating income	224	191	635	574
Intersegment sales
Segment Reporting Information [Line Items]
Sales	(439)	(421)	(1,259)	(1,202)
Operating income	(56)	(57)	(157)	(156)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net FAS (service)/ CAS pension adjustment	108	131	316	346
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating income	$ (172)	$ (135)	$ (450)	$ (439)