Arrangements With Off-Balance Sheet Risk (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Sep. 30, 2019	Dec. 31, 2018
ULA [Member]
Guarantees [Line Items]
Delta launch program inventories included in contributed assets			$ 1,360
Delta launch program inventories subject to inventory supply agreement			1,860
Contributed Delta Program Launch Inventory [Member] | ULA [Member]
Guarantees [Line Items]
Maximum Potential Payments			30	$ 52
Other Delta Contracts [Member] | Deferred support costs [Member]
Guarantees [Line Items]
Maximum Potential Payments			85
Additional potentially unrecoverable deferred production costs		$ 271
Other Delta Contracts [Member] | Deferred production costs [Member]
Guarantees [Line Items]
Maximum Potential Payments			91
Additional potentially unrecoverable deferred production costs	$ 114
Other Delta Contracts [Member] | ULA [Member]
Guarantees [Line Items]
Maximum Potential Payments			176	176
Carrying Amount of Liabilities
Deferred Support and Production Costs [Member]
Guarantees [Line Items]
Loss Contingency, Estimate of Possible Loss			317
Credit Guarantee [Member]
Guarantees [Line Items]
Maximum Potential Payments			92	106
Carrying Amount of Liabilities			$ 16	$ 16