Segment Information Reconciliation to Consolidated Operating Income (Details 1) $ in Millions	3 Months Ended								7 Months Ended	12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Number of reportable segments										4
Sales	$ 10,212	$ 9,083	$ 8,884	$ 8,620	$ 8,721	$ 8,475	$ 8,456	$ 8,189		$ 36,799	$ 33,841	$ 30,095
Operating income	$ 1,152	$ 985	$ 994	$ 934	$ 1,136	$ 951	$ 946	$ 936		4,065	3,969	3,780
Operating Segments
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income										4,188	3,978	3,514
Operating Segments | Aeronautics Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										12,169	11,116	10,293
Operating income										1,206	1,188	1,128
Operating Segments | Defense Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										7,543	7,495	6,612
Operating income										846	793	697
Operating Segments | Mission Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										10,080	9,410	8,949
Operating income										1,459	1,408	1,245
Operating Segments | Space Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales									$ 3,100	8,744	7,425	5,845
Operating income									$ 342	893	794	644
Intersegment sales
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										1,737	1,605	1,604
Operating income										216	205	200
Intersegment sales | Aeronautics Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										122	103	73
Operating income										11	10	8
Intersegment sales | Defense Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										728	691	750
Operating income										76	74	74
Intersegment sales | Mission Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										779	728	718
Operating income										116	113	115
Intersegment sales | Space Systems
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Sales										108	83	63
Operating income										13	8	3
Corporate, Non-Segment [Member]
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Operating income										(541)	(474)	(347)
Segment Reconciling Items [Member]
Sales and Service Revenues by Segment (Table Amounts) [Abstract]
Net FAS (service)/ CAS pension adjustment										$ 418	$ 465	$ 613