Segment Information (Unaudited) Sales by Customer Type (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue, Major Customer [Line Items]
Sales	$ 9,083	$ 8,475	$ 26,587	$ 25,120
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
U.S. government(1)
Revenue, Major Customer [Line Items]
Sales	$ 7,659	$ 7,066	$ 22,222	$ 20,767
Concentration Risk, Percentage	84.00%	83.00%	84.00%	83.00%
U.S. government(1) | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,491	$ 2,334	$ 7,329	$ 6,906
Concentration Risk, Percentage	85.00%	84.00%	84.00%	83.00%
U.S. government(1) | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,264	$ 1,299	$ 3,828	$ 3,721
Concentration Risk, Percentage	68.00%	67.00%	68.00%	66.00%
U.S. government(1) | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,884	$ 1,690	$ 5,331	$ 5,049
Concentration Risk, Percentage	74.00%	73.00%	73.00%	73.00%
U.S. government(1) | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,020	$ 1,743	$ 5,734	$ 5,091
Concentration Risk, Percentage	92.00%	93.00%	93.00%	93.00%
International(2)
Revenue, Major Customer [Line Items]
Sales	$ 1,243	$ 1,205	$ 3,839	$ 3,723
Concentration Risk, Percentage	14.00%	14.00%	14.00%	15.00%
International(2) | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 382	$ 390	$ 1,233	$ 1,264
Concentration Risk, Percentage	13.00%	14.00%	14.00%	15.00%
International(2) | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 307	$ 347	$ 963	$ 1,075
Concentration Risk, Percentage	17.00%	18.00%	17.00%	19.00%
International(2) | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 455	$ 407	$ 1,406	$ 1,248
Concentration Risk, Percentage	18.00%	18.00%	19.00%	18.00%
International(2) | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 99	$ 61	$ 237	$ 136
Concentration Risk, Percentage	5.00%	3.00%	4.00%	3.00%
Other customers
Revenue, Major Customer [Line Items]
Sales	$ 181	$ 204	$ 526	$ 630
Concentration Risk, Percentage	2.00%	3.00%	2.00%	2.00%
Other customers | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 11	$ 19	$ 35	$ 64
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Other customers | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 97	$ 106	$ 293	$ 309
Concentration Risk, Percentage	5.00%	6.00%	5.00%	6.00%
Other customers | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 19	$ 22	$ 54	$ 75
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Other customers | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 54	$ 57	$ 144	$ 182
Concentration Risk, Percentage	2.00%	3.00%	2.00%	3.00%
Intersegment Sales [Member] | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 30	$ 27	$ 85	$ 75
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Intersegment Sales [Member] | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 191	$ 179	$ 542	$ 510
Concentration Risk, Percentage	10.00%	9.00%	10.00%	9.00%
Intersegment Sales [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 193	$ 191	$ 553	$ 552
Concentration Risk, Percentage	7.00%	8.00%	7.00%	8.00%
Intersegment Sales [Member] | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 25	$ 24	$ 79	$ 65
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,914	$ 2,770	$ 8,682	$ 8,309
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,859	$ 1,931	$ 5,626	$ 5,615
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,551	$ 2,310	$ 7,344	$ 6,924
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,198	$ 1,885	$ 6,194	$ 5,474
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%