Business Segment Reporting (Capital Expenditures) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Capital expenditures	$ 940	$ 798	$ 634
Operating Segments [Member] | Integrated Defense Systems
Segment Reporting Information [Line Items]
Capital expenditures	309	242	200
Operating Segments [Member] | Intelligence, Information and Services
Segment Reporting Information [Line Items]
Capital expenditures	50	46	22
Operating Segments [Member] | Missile Systems
Segment Reporting Information [Line Items]
Capital expenditures	232	337	221
Operating Segments [Member] | Space and Airborne Systems
Segment Reporting Information [Line Items]
Capital expenditures	304	136	158
Operating Segments [Member] | Forcepoint
Segment Reporting Information [Line Items]
Capital expenditures	17	13	14
Corporate [Member]
Segment Reporting Information [Line Items]
Capital expenditures	$ 28	$ 24	$ 19