Segment Information Capital Expenditures and Depreciation and Amortization (Details 7) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	$ 1,420	$ 1,264	$ 1,249
Depreciation and amortization	1,267	1,265	800
Other Depreciation and Amortization	1,005	1,018	800
Aeronautics Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	540	528	657
Depreciation and amortization	238	224	190
Defense Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	78	71	66
Depreciation and amortization	48	44	65
Mission Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	302	229	197
Depreciation and amortization	150	133	121
Space Systems
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	440	352	226
Depreciation and amortization	211	189	130
Corporate
Additional information by Segment (Table Amounts) [Abstract]
Capital Expenditures	60	84	103
Depreciation and amortization	$ 358	$ 428	$ 294