Segment Information (Unaudited) Sales by Contract Type (Details 3) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue, Contract Type [Line Items]
Sales	$ 9,151	$ 8,884	$ 18,308	$ 17,504
Sales percentage	100.00%	100.00%	100.00%	100.00%
Cost-type [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,608	$ 4,371	$ 9,237	$ 8,586
Sales percentage	50.00%	49.00%	50.00%	49.00%
Cost-type [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,341	$ 1,426	$ 2,752	$ 2,769
Sales percentage	47.00%	49.00%	47.00%	48.00%
Cost-type [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 434	$ 582	$ 943	$ 1,210
Sales percentage	35.00%	34.00%	36.00%	35.00%
Cost-type [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 808	$ 895	$ 1,673	$ 1,741
Sales percentage	35.00%	40.00%	36.00%	39.00%
Cost-type [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,025	$ 1,468	$ 3,869	$ 2,866
Sales percentage	75.00%	73.00%	74.00%	73.00%
Fixed-price [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,543	$ 4,513	$ 9,071	$ 8,918
Sales percentage	50.00%	51.00%	50.00%	51.00%
Fixed-price [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,527	$ 1,470	$ 3,062	$ 2,944
Sales percentage	53.00%	51.00%	53.00%	52.00%
Fixed-price [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 798	$ 1,124	$ 1,666	$ 2,206
Sales percentage	65.00%	66.00%	64.00%	65.00%
Fixed-price [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,526	$ 1,367	$ 3,013	$ 2,692
Sales percentage	65.00%	60.00%	64.00%	61.00%
Fixed-price [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 692	$ 552	$ 1,330	$ 1,076
Sales percentage	25.00%	27.00%	26.00%	27.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 45	$ 29	$ 89	$ 55
Intersegment sales | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	195	180	380	351
Intersegment sales | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	254	184	491	360
Intersegment sales | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	31	28	70	54
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,913	$ 2,925	$ 5,903	$ 5,768
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,427	$ 1,886	$ 2,989	$ 3,767
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,588	$ 2,446	$ 5,177	$ 4,793
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,748	$ 2,048	$ 5,269	$ 3,996
Sales percentage	100.00%	100.00%	100.00%	100.00%