Segment Information (Unaudited) (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Major Customer [Line Items]
Sales	$ 8,085	$ 6,569	$ 21,939	$ 19,452
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
US Government [Member]
Revenue, Major Customer [Line Items]
Sales	$ 6,711	$ 5,547	$ 18,227	$ 16,437
Concentration Risk, Percentage	83.00%	85.00%	83.00%	85.00%
US Government [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,926	$ 2,724	$ 8,633	$ 7,893
Concentration Risk, Percentage	89.00%	87.00%	87.00%	87.00%
US Government [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 972	$ 0	$ 1,237	$ 0
Concentration Risk, Percentage	69.00%	0.00%	68.00%	0.00%
US Government [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,232	$ 2,193	$ 6,577	$ 6,606
Concentration Risk, Percentage	77.00%	77.00%	76.00%	78.00%
US Government [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 581	$ 630	$ 1,780	$ 1,938
Concentration Risk, Percentage	56.00%	53.00%	55.00%	55.00%
International Customer [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,099	$ 865	$ 3,094	$ 2,530
Concentration Risk, Percentage	14.00%	13.00%	14.00%	13.00%
International Customer [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 270	$ 295	$ 990	$ 876
Concentration Risk, Percentage	8.00%	10.00%	10.00%	10.00%
International Customer [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 272	$ 0	$ 364	$ 0
Concentration Risk, Percentage	19.00%	0.00%	20.00%	0.00%
International Customer [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 374	$ 383	$ 1,144	$ 1,090
Concentration Risk, Percentage	12.00%	14.00%	13.00%	13.00%
International Customer [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 183	$ 187	$ 596	$ 564
Concentration Risk, Percentage	17.00%	16.00%	18.00%	16.00%
Other Customers [Member]
Revenue, Major Customer [Line Items]
Sales	$ 275	$ 157	$ 618	$ 485
Concentration Risk, Percentage	3.00%	2.00%	3.00%	2.00%
Other Customers [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 44	$ 36	$ 124	$ 114
Concentration Risk, Percentage	2.00%	1.00%	1.00%	1.00%
Other Customers [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 134	$ 0	$ 164	$ 0
Concentration Risk, Percentage	9.00%	0.00%	9.00%	0.00%
Other Customers [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 25	$ 27	$ 89	$ 81
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Other Customers [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 72	$ 94	$ 241	$ 290
Concentration Risk, Percentage	7.00%	8.00%	8.00%	8.00%
Intersegment Eliminations [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 42	$ 70	$ 152	$ 229
Concentration Risk, Percentage	1.00%	2.00%	2.00%	2.00%
Intersegment Eliminations [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 37	$ 0	$ 50	$ 0
Concentration Risk, Percentage	3.00%	0.00%	3.00%	0.00%
Intersegment Eliminations [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 280	$ 233	$ 858	$ 718
Concentration Risk, Percentage	10.00%	8.00%	10.00%	8.00%
Intersegment Eliminations [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 204	$ 272	$ 615	$ 743
Concentration Risk, Percentage	20.00%	23.00%	19.00%	21.00%
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 3,282	$ 3,125	$ 9,899	$ 9,112
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,415	$ 0	$ 1,815	$ 0
Concentration Risk, Percentage	100.00%	0.00%	100.00%	0.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,911	$ 2,836	$ 8,668	$ 8,495
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,040	$ 1,183	$ 3,232	$ 3,535
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%