Segment Information (Unaudited) Sales by Contract Type (Details 3) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue, Contract Type [Line Items]
Sales	$ 8,720	$ 9,083	$ 27,028	$ 26,587
Sales percentage	100.00%	100.00%	100.00%	100.00%
Cost-type [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,468	$ 4,496	$ 13,705	$ 13,082
Sales percentage	51.00%	49.00%	51.00%	49.00%
Cost-type [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,358	$ 1,436	$ 4,110	$ 4,205
Sales percentage	51.00%	50.00%	48.00%	49.00%
Cost-type [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 433	$ 549	$ 1,376	$ 1,759
Sales percentage	36.00%	33.00%	36.00%	35.00%
Cost-type [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 746	$ 948	$ 2,419	$ 2,689
Sales percentage	34.00%	40.00%	35.00%	40.00%
Cost-type [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,931	$ 1,563	$ 5,800	$ 4,429
Sales percentage	73.00%	72.00%	74.00%	72.00%
Fixed-price [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,252	$ 4,587	$ 13,323	$ 13,505
Sales percentage	49.00%	51.00%	49.00%	51.00%
Fixed-price [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,319	$ 1,448	$ 4,381	$ 4,392
Sales percentage	49.00%	50.00%	52.00%	51.00%
Fixed-price [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 770	$ 1,119	$ 2,436	$ 3,325
Sales percentage	64.00%	67.00%	64.00%	65.00%
Fixed-price [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,446	$ 1,410	$ 4,459	$ 4,102
Sales percentage	66.00%	60.00%	65.00%	60.00%
Fixed-price [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 717	$ 610	$ 2,047	$ 1,686
Sales percentage	27.00%	28.00%	26.00%	28.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 48	$ 30	$ 137	$ 85
Intersegment sales | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	206	191	586	542
Intersegment sales | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	244	193	735	553
Intersegment sales | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	33	25	103	79
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,725	$ 2,914	$ 8,628	$ 8,682
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,409	$ 1,859	$ 4,398	$ 5,626
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,436	$ 2,551	$ 7,613	$ 7,344
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,681	$ 2,198	$ 7,950	$ 6,194
Sales percentage	100.00%	100.00%	100.00%	100.00%