Segment Information (Unaudited) Sales by Contract Type (Details 3) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue, Contract Type [Line Items]
Sales	$ 8,620	$ 8,189
Concentration Risk, Percentage	100.00%	100.00%
Cost-type [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,215	$ 4,076
Concentration Risk, Percentage	49.00%	50.00%
Cost-type [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,343	$ 1,312
Concentration Risk, Percentage	48.00%	47.00%
Cost-type [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 628	$ 623
Concentration Risk, Percentage	37.00%	39.00%
Cost-type [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 846	$ 835
Concentration Risk, Percentage	39.00%	41.00%
Cost-type [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,398	$ 1,306
Concentration Risk, Percentage	73.00%	73.00%
Fixed-price [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,405	$ 4,113
Concentration Risk, Percentage	51.00%	50.00%
Fixed-price [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,474	$ 1,482
Concentration Risk, Percentage	52.00%	53.00%
Fixed-price [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,082	$ 978
Concentration Risk, Percentage	63.00%	61.00%
Fixed-price [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,325	$ 1,178
Concentration Risk, Percentage	61.00%	59.00%
Fixed-price [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 524	$ 475
Concentration Risk, Percentage	27.00%	27.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 26	$ 24
Intersegment sales | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	171	167
Intersegment sales | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	176	197
Intersegment sales | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	26	20
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,843	$ 2,818
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,881	$ 1,768
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,347	$ 2,210
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,948	$ 1,801
Concentration Risk, Percentage	100.00%	100.00%