Segment Information (Unaudited) Sales by Geographic Location (Details 4) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue, Geographic Location [Line Items]
Sales	$ 9,151	$ 8,884	$ 18,308	$ 17,504
Sales percentage	100.00%	100.00%	100.00%	100.00%
United States
Revenue, Geographic Location [Line Items]
Sales	$ 7,943	$ 7,623	$ 15,742	$ 14,908
Sales percentage	86.00%	86.00%	86.00%	85.00%
United States | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,517	$ 2,489	$ 5,064	$ 4,862
Sales percentage	88.00%	86.00%	87.00%	85.00%
United States | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 897	$ 1,390	$ 1,923	$ 2,760
Sales percentage	73.00%	82.00%	73.00%	81.00%
United States | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,915	$ 1,794	$ 3,765	$ 3,482
Sales percentage	82.00%	79.00%	80.00%	79.00%
United States | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,614	$ 1,950	$ 4,990	$ 3,804
Sales percentage	97.00%	97.00%	96.00%	97.00%
Asia/Pacific
Revenue, Geographic Location [Line Items]
Sales	$ 441	$ 505	$ 999	$ 975
Sales percentage	5.00%	6.00%	5.00%	6.00%
Asia/Pacific | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 204	$ 202	$ 483	$ 409
Sales percentage	7.00%	7.00%	8.00%	7.00%
Asia/Pacific | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 126	$ 107	$ 229	$ 189
Sales percentage	10.00%	6.00%	9.00%	5.00%
Asia/Pacific | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 98	$ 191	$ 258	$ 367
Sales percentage	4.00%	9.00%	6.00%	8.00%
Asia/Pacific | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 13	$ 5	$ 29	$ 10
Sales percentage			1.00%
Europe
Revenue, Geographic Location [Line Items]
Sales	$ 537	$ 474	$ 1,070	$ 994
Sales percentage	6.00%	5.00%	6.00%	6.00%
Europe | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 127	$ 150	$ 227	$ 316
Sales percentage	4.00%	5.00%	4.00%	6.00%
Europe | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 79	$ 70	$ 155	$ 140
Sales percentage	6.00%	4.00%	6.00%	4.00%
Europe | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 242	$ 191	$ 511	$ 416
Sales percentage	11.00%	9.00%	11.00%	9.00%
Europe | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 89	$ 63	$ 177	$ 122
Sales percentage	3.00%	3.00%	3.00%	3.00%
All other
Revenue, Geographic Location [Line Items]
Sales	$ 230	$ 282	$ 497	$ 627
Sales percentage	3.00%	3.00%	3.00%	3.00%
All other | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 20	$ 55	$ 40	$ 126
Sales percentage	1.00%	2.00%	1.00%	2.00%
All other | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 130	$ 139	$ 302	$ 327
Sales percentage	11.00%	8.00%	12.00%	10.00%
All other | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 79	$ 86	$ 152	$ 168
Sales percentage	3.00%	3.00%	3.00%	4.00%
All other | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1	$ 2	$ 3	$ 6
Intersegment sales | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	45	29	89	55
Intersegment sales | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	195	180	380	351
Intersegment sales | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	254	184	491	360
Intersegment sales | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	31	28	70	54
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,913	$ 2,925	$ 5,903	$ 5,768
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 1,427	$ 1,886	$ 2,989	$ 3,767
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,588	$ 2,446	$ 5,177	$ 4,793
Sales percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Geographic Location [Line Items]
Sales	$ 2,748	$ 2,048	$ 5,269	$ 3,996
Sales percentage	100.00%	100.00%	100.00%	100.00%