Segment Information (Unaudited) Sales by Contract Type (Details 3) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Contract Type [Line Items]
Sales	$ 8,884	$ 8,456	$ 17,504	$ 16,645
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Cost-type [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,371	$ 4,112	$ 8,586	$ 8,188
Concentration Risk, Percentage	49.00%	49.00%	49.00%	49.00%
Cost-type [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,426	$ 1,312	$ 2,769	$ 2,624
Concentration Risk, Percentage	49.00%	49.00%	48.00%	48.00%
Cost-type [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 582	$ 632	$ 1,210	$ 1,255
Concentration Risk, Percentage	34.00%	36.00%	35.00%	37.00%
Cost-type [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 895	$ 870	$ 1,741	$ 1,705
Concentration Risk, Percentage	40.00%	39.00%	39.00%	40.00%
Cost-type [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,468	$ 1,298	$ 2,866	$ 2,604
Concentration Risk, Percentage	73.00%	73.00%	73.00%	73.00%
Fixed-price [Member]
Revenue, Contract Type [Line Items]
Sales	$ 4,513	$ 4,344	$ 8,918	$ 8,457
Concentration Risk, Percentage	51.00%	51.00%	51.00%	51.00%
Fixed-price [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,470	$ 1,385	$ 2,944	$ 2,867
Concentration Risk, Percentage	51.00%	51.00%	52.00%	52.00%
Fixed-price [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,124	$ 1,120	$ 2,206	$ 2,098
Concentration Risk, Percentage	66.00%	64.00%	65.00%	63.00%
Fixed-price [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,367	$ 1,370	$ 2,692	$ 2,548
Concentration Risk, Percentage	60.00%	61.00%	61.00%	60.00%
Fixed-price [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 552	$ 469	$ 1,076	$ 944
Concentration Risk, Percentage	27.00%	27.00%	27.00%	27.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 29	$ 24	$ 55	$ 48
Intersegment sales | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	180	164	351	331
Intersegment sales | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	184	164	360	361
Intersegment sales | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	28	21	54	41
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,925	$ 2,721	$ 5,768	$ 5,539
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 1,886	$ 1,916	$ 3,767	$ 3,684
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,446	$ 2,404	$ 4,793	$ 4,614
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Contract Type [Line Items]
Sales	$ 2,048	$ 1,788	$ 3,996	$ 3,589
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%