Business Segment Reporting (Depreciation and Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Depreciation and Amortization	$ 605	$ 568	$ 550
Operating Segments [Member] | Integrated Defense Systems
Segment Reporting Information [Line Items]
Depreciation and Amortization	118	98	98
Operating Segments [Member] | Intelligence, Information and Services
Segment Reporting Information [Line Items]
Depreciation and Amortization	49	51	50
Operating Segments [Member] | Missile Systems
Segment Reporting Information [Line Items]
Depreciation and Amortization	129	98	84
Operating Segments [Member] | Space and Airborne Systems
Segment Reporting Information [Line Items]
Depreciation and Amortization	132	140	132
Operating Segments [Member] | Forcepoint
Segment Reporting Information [Line Items]
Depreciation and Amortization	14	17	17
Segment Reconciling Items [Member] | Acquisition Accounting Adjustment [Member]
Segment Reporting Information [Line Items]
Depreciation and Amortization	111	116	125
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation and Amortization	$ 52	$ 48	$ 44