Segment Information (Unaudited) (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue, Major Customer [Line Items]
Sales	$ 8,475	$ 8,085	$ 25,120	$ 21,939
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
U.S. government (1)
Revenue, Major Customer [Line Items]
Sales	$ 7,066	$ 6,711	$ 20,767	$ 18,227
Concentration Risk, Percentage	83.00%	83.00%	83.00%	83.00%
U.S. government (1) | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 3,014	$ 2,926	$ 8,954	$ 8,633
Concentration Risk, Percentage	87.00%	89.00%	87.00%	87.00%
U.S. government (1) | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,163	$ 972	$ 3,239	$ 1,237
Concentration Risk, Percentage	74.00%	69.00%	72.00%	68.00%
U.S. government (1) | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,260	$ 2,232	$ 6,775	$ 6,577
Concentration Risk, Percentage	75.00%	77.00%	75.00%	76.00%
U.S. government (1) | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 629	$ 581	$ 1,799	$ 1,780
Concentration Risk, Percentage	59.00%	56.00%	58.00%	55.00%
International (2)
Revenue, Major Customer [Line Items]
Sales	$ 1,205	$ 1,099	$ 3,723	$ 3,094
Concentration Risk, Percentage	14.00%	14.00%	15.00%	14.00%
International (2) | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 353	$ 270	$ 1,137	$ 990
Concentration Risk, Percentage	10.00%	8.00%	11.00%	10.00%
International (2) | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 228	$ 272	$ 702	$ 364
Concentration Risk, Percentage	14.00%	19.00%	16.00%	20.00%
International (2) | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 416	$ 374	$ 1,242	$ 1,144
Concentration Risk, Percentage	14.00%	12.00%	14.00%	13.00%
International (2) | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 208	$ 183	$ 642	$ 596
Concentration Risk, Percentage	19.00%	17.00%	21.00%	18.00%
Other customers
Revenue, Major Customer [Line Items]
Sales	$ 204	$ 275	$ 630	$ 618
Concentration Risk, Percentage	3.00%	3.00%	2.00%	3.00%
Other customers | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 36	$ 44	$ 100	$ 124
Concentration Risk, Percentage	1.00%	2.00%	1.00%	1.00%
Other customers | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 99	$ 134	$ 331	$ 164
Concentration Risk, Percentage	6.00%	9.00%	7.00%	9.00%
Other customers | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 32	$ 25	$ 105	$ 89
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Other customers | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 37	$ 72	$ 94	$ 241
Concentration Risk, Percentage	4.00%	7.00%	3.00%	8.00%
Intersegment Sales [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 55	$ 42	$ 153	$ 152
Concentration Risk, Percentage	2.00%	1.00%	1.00%	2.00%
Intersegment Sales [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 94	$ 37	$ 248	$ 50
Concentration Risk, Percentage	6.00%	3.00%	5.00%	3.00%
Intersegment Sales [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 321	$ 280	$ 921	$ 858
Concentration Risk, Percentage	10.00%	10.00%	10.00%	10.00%
Intersegment Sales [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 193	$ 204	$ 553	$ 615
Concentration Risk, Percentage	18.00%	20.00%	18.00%	19.00%
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 3,458	$ 3,282	$ 10,344	$ 9,899
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,584	$ 1,415	$ 4,520	$ 1,815
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 3,029	$ 2,911	$ 9,043	$ 8,668
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,067	$ 1,040	$ 3,088	$ 3,232
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%