Segment Information (Unaudited) Sales by Contract Type (Details 3) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue, Contract Type [Line Items]
Sales	$ 9,157	$ 8,620
Concentration Risk, Percentage	100.00%	100.00%
Cost-type [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,629	$ 4,215
Concentration Risk, Percentage	51.00%	49.00%
Cost-type [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,411	$ 1,343
Concentration Risk, Percentage	48.00%	48.00%
Cost-type [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 509	$ 628
Concentration Risk, Percentage	37.00%	37.00%
Cost-type [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 865	$ 846
Concentration Risk, Percentage	37.00%	39.00%
Cost-type [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,844	$ 1,398
Concentration Risk, Percentage	74.00%	73.00%
Fixed-price [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,528	$ 4,405
Concentration Risk, Percentage	49.00%	51.00%
Fixed-price [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,535	$ 1,474
Concentration Risk, Percentage	52.00%	52.00%
Fixed-price [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 868	$ 1,082
Concentration Risk, Percentage	63.00%	63.00%
Fixed-price [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,487	$ 1,325
Concentration Risk, Percentage	63.00%	61.00%
Fixed-price [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 638	$ 524
Concentration Risk, Percentage	26.00%	27.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 44	$ 26
Intersegment sales | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	185	171
Intersegment sales | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	237	176
Intersegment sales | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	39	26
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,990	$ 2,843
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,562	$ 1,881
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,589	$ 2,347
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,521	$ 1,948
Concentration Risk, Percentage	100.00%	100.00%