Segment Information (Unaudited) (Details 2) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue, Major Customer [Line Items]
Sales	$ 7,119	$ 6,473	$ 13,854	$ 12,883
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
US Government [Member]
Revenue, Major Customer [Line Items]
Sales	$ 5,816	$ 5,515	$ 11,516	$ 10,890
Concentration Risk, Percentage	82.00%	85.00%	83.00%	84.00%
US Government [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,799	$ 2,616	$ 5,707	$ 5,169
Concentration Risk, Percentage	84.00%	87.00%	86.00%	86.00%
US Government [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 265	$ 0	$ 265	$ 0
Concentration Risk, Percentage	66.00%	0.00%	66.00%	0.00%
US Government [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,155	$ 2,227	$ 4,345	$ 4,413
Concentration Risk, Percentage	75.00%	78.00%	76.00%	78.00%
US Government [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 597	$ 672	$ 1,199	$ 1,308
Concentration Risk, Percentage	57.00%	58.00%	54.00%	56.00%
International Customer [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,125	$ 793	$ 1,995	$ 1,665
Concentration Risk, Percentage	16.00%	12.00%	15.00%	13.00%
International Customer [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 449	$ 272	$ 720	$ 581
Concentration Risk, Percentage	13.00%	9.00%	11.00%	10.00%
International Customer [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 92	$ 0	$ 92	$ 0
Concentration Risk, Percentage	23.00%	0.00%	23.00%	0.00%
International Customer [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 391	$ 353	$ 770	$ 707
Concentration Risk, Percentage	14.00%	12.00%	13.00%	12.00%
International Customer [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 193	$ 168	$ 413	$ 377
Concentration Risk, Percentage	18.00%	14.00%	19.00%	16.00%
Other Customers [Member]
Revenue, Major Customer [Line Items]
Sales	$ 178	$ 165	$ 343	$ 328
Concentration Risk, Percentage	2.00%	3.00%	2.00%	3.00%
Other Customers [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 38	$ 40	$ 80	$ 78
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Other Customers [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 30	$ 0	$ 30	$ 0
Concentration Risk, Percentage	8.00%	0.00%	8.00%	0.00%
Other Customers [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 34	$ 33	$ 64	$ 54
Concentration Risk, Percentage	1.00%	1.00%	1.00%	1.00%
Other Customers [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 76	$ 92	$ 169	$ 196
Concentration Risk, Percentage	7.00%	8.00%	8.00%	8.00%
Intersegment Eliminations [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 51	$ 75	$ 110	$ 159
Concentration Risk, Percentage	2.00%	3.00%	2.00%	3.00%
Intersegment Eliminations [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 13	$ 0	$ 13	$ 0
Concentration Risk, Percentage	3.00%	0.00%	3.00%	0.00%
Intersegment Eliminations [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 294	$ 246	$ 578	$ 485
Concentration Risk, Percentage	10.00%	9.00%	10.00%	9.00%
Intersegment Eliminations [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 182	$ 230	$ 411	$ 471
Concentration Risk, Percentage	18.00%	20.00%	19.00%	20.00%
Operating Segments [Member] | Aerospace Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 3,337	$ 3,003	$ 6,617	$ 5,987
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Innovation Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 400	$ 0	$ 400	$ 0
Concentration Risk, Percentage	100.00%	0.00%	100.00%	0.00%
Operating Segments [Member] | Mission Systems [Member]
Revenue, Major Customer [Line Items]
Sales	$ 2,874	$ 2,859	$ 5,757	$ 5,659
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%
Operating Segments [Member] | Technology Services [Member]
Revenue, Major Customer [Line Items]
Sales	$ 1,048	$ 1,162	$ 2,192	$ 2,352
Concentration Risk, Percentage	100.00%	100.00%	100.00%	100.00%