Segment Information (Unaudited) Sales by Geographic Location (Details 4) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Geographic Location [Line Items]
Sales	$ 8,884	$ 8,456	$ 17,504	$ 16,645
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
United States
Revenue, Geographic Location [Line Items]
Sales	$ 7,623	$ 7,155	$ 14,908	$ 14,127
Concentration Risk, Percentage	86.00%	84.00%	85.00%	85.00%
United States | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,489	$ 2,258	$ 4,862	$ 4,617
Concentration Risk, Percentage	86.00%	84.00%	85.00%	84.00%
United States | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,390	$ 1,387	$ 2,760	$ 2,625
Concentration Risk, Percentage	82.00%	79.00%	81.00%	78.00%
United States | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,794	$ 1,775	$ 3,482	$ 3,412
Concentration Risk, Percentage	79.00%	79.00%	79.00%	80.00%
United States | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,950	$ 1,735	$ 3,804	$ 3,473
Concentration Risk, Percentage	97.00%	98.00%	97.00%	98.00%
Asia/Pacific
Revenue, Geographic Location [Line Items]
Sales	$ 505	$ 484	$ 975	$ 952
Concentration Risk, Percentage	6.00%	6.00%	6.00%	6.00%
Asia/Pacific | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 202	$ 215	$ 409	$ 448
Concentration Risk, Percentage	7.00%	8.00%	7.00%	8.00%
Asia/Pacific | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 107	$ 125	$ 189	$ 213
Concentration Risk, Percentage	6.00%	7.00%	5.00%	6.00%
Asia/Pacific | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 191	$ 142	$ 367	$ 277
Concentration Risk, Percentage	9.00%	6.00%	8.00%	7.00%
Asia/Pacific | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 5	$ 2	$ 10	$ 14
Concentration Risk, Percentage	0.00%	0.00%	0.00%	0.00%
All other
Revenue, Geographic Location [Line Items]
Sales	$ 756	$ 817	$ 1,621	$ 1,566
Concentration Risk, Percentage	8.00%	10.00%	9.00%	9.00%
All other | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 205	$ 224	$ 442	$ 426
Concentration Risk, Percentage	7.00%	8.00%	8.00%	8.00%
All other | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 209	$ 240	$ 467	$ 515
Concentration Risk, Percentage	12.00%	14.00%	14.00%	16.00%
All other | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 277	$ 323	$ 584	$ 564
Concentration Risk, Percentage	12.00%	15.00%	13.00%	13.00%
All other | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 65	$ 30	$ 128	$ 61
Concentration Risk, Percentage	3.00%	2.00%	3.00%	2.00%
Intersegment sales | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 29	$ 24	$ 55	$ 48
Intersegment sales | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	180	164	351	331
Intersegment sales | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	184	164	360	361
Intersegment sales | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	28	21	54	41
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Geographic Location [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, Geographic Location [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, Geographic Location [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, Geographic Location [Line Items]
Sales	$ 2,048	$ 1,788	$ 3,996	$ 3,589
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%