Arrangements With Off-Balance Sheet Risk (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2018	Dec. 31, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potentially Unrecoverable Costs Under Contracts	$ 114	$ 271
Offsetting capital lease obligation and IRB asset			$ 271	$ 166
ULA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Delta launch program inventories included in contributed assets			1,360
Delta launch program inventories subject to an inventory supply agreement			1,860
Contributed Delta Program Launch Inventory [Member] | ULA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			52	72
Contract Pricing [Member] | ULA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			261	261
Payments received due to settlement agreement			240
Carrying Amount of Liabilities				7
Other Delta Contracts [Member] | Deferred support costs [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			85
Other Delta Contracts [Member] | Deferred production costs [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			91
Other Delta Contracts [Member] | ULA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			176	191
Carrying Amount of Liabilities
Deferred Support and Production Costs [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Loss Contingency, Estimate of Possible Loss			317
Credit Guarantees [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			106	109
Carrying Amount of Liabilities			$ 16	$ 16