Business Segment Reporting (Components of Total Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 34,566	$ 32,670
Operating Segments [Member] | Integrated Defense Systems
Segment Reporting Information [Line Items]
Total assets	5,103	4,826
Operating Segments [Member] | Intelligence, Information and Services
Segment Reporting Information [Line Items]
Total assets	4,291	4,238
Operating Segments [Member] | Missile Systems
Segment Reporting Information [Line Items]
Total assets	8,408	8,229
Operating Segments [Member] | Space and Airborne Systems
Segment Reporting Information [Line Items]
Total assets	6,979	6,740
Operating Segments [Member] | Forcepoint
Segment Reporting Information [Line Items]
Total assets	2,424	2,529
Corporate [Member]
Segment Reporting Information [Line Items]
Total assets	$ 7,361	$ 6,108