Segment Information (Details 3) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total assets	$ 34,917	$ 25,614
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	21,663	20,596
Operating Segments [Member] | Aerospace Systems
Segment Reporting Information [Line Items]
Total assets	8,449	7,523
Operating Segments [Member] | Mission Systems
Segment Reporting Information [Line Items]
Total assets	10,204	9,991
Operating Segments [Member] | Technology Services
Segment Reporting Information [Line Items]
Total assets	3,010	3,082
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 13,254	$ 5,018