Segment Information (Unaudited) Sales by Customer Type (Details 2) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue, Major Customer [Line Items]
Sales	$ 8,620	$ 8,189
Concentration Risk, Percentage	100.00%	100.00%
U.S. government(1)
Revenue, Major Customer [Line Items]
Sales	$ 7,094	$ 6,757
Concentration Risk, Percentage	83.00%	83.00%
U.S. government(1) | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,361	$ 2,334
Concentration Risk, Percentage	83.00%	83.00%
U.S. government(1) | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,259	$ 1,141
Concentration Risk, Percentage	67.00%	65.00%
U.S. government(1) | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,671	$ 1,613
Concentration Risk, Percentage	71.00%	73.00%
U.S. government(1) | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,803	$ 1,669
Concentration Risk, Percentage	93.00%	93.00%
International(2)
Revenue, Major Customer [Line Items]
Sales	$ 1,335	$ 1,217
Concentration Risk, Percentage	15.00%	15.00%
International(2) | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 444	$ 435
Concentration Risk, Percentage	16.00%	15.00%
International(2) | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 340	$ 363
Concentration Risk, Percentage	18.00%	21.00%
International(2) | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 483	$ 376
Concentration Risk, Percentage	21.00%	17.00%
International(2) | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 68	$ 43
Concentration Risk, Percentage	3.00%	2.00%
Other customers
Revenue, Major Customer [Line Items]
Sales	$ 191	$ 215
Concentration Risk, Percentage	2.00%	2.00%
Other customers | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 12	$ 25
Concentration Risk, Percentage	0.00%	1.00%
Other customers | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 111	$ 97
Concentration Risk, Percentage	6.00%	5.00%
Other customers | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 17	$ 24
Concentration Risk, Percentage	1.00%	1.00%
Other customers | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 51	$ 69
Concentration Risk, Percentage	3.00%	4.00%
Intersegment Sales [Member] | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 26	$ 24
Concentration Risk, Percentage	1.00%	1.00%
Intersegment Sales [Member] | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 171	$ 167
Concentration Risk, Percentage	9.00%	9.00%
Intersegment Sales [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 176	$ 197
Concentration Risk, Percentage	7.00%	9.00%
Intersegment Sales [Member] | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 26	$ 20
Concentration Risk, Percentage	1.00%	1.00%
Operating Segments [Member] | Aeronautics Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,843	$ 2,818
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Defense Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,881	$ 1,768
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,347	$ 2,210
Concentration Risk, Percentage	100.00%	100.00%
Operating Segments [Member] | Space Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,948	$ 1,801
Concentration Risk, Percentage	100.00%	100.00%