Arrangements With Off-Balance Sheet Risk (Narrative) (Details) $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2011 USD ($)	Jun. 30, 2011 USD ($)	Dec. 31, 2016 USD ($) satellites	Dec. 31, 2015 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of satellite missions | satellites			4
Potentially Unrecoverable Costs Under Contracts	$ 114	$ 271
Offsetting capital lease obligation and IRB asset			$ 64	$ 584
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 inventories consumed by ULA			1,283
Inventory Supply Agreement Payments Received			1,740
Payments made under inventory supply agreement			63
Inventory Supply Agreement Revenue and Costs of Sales Recorded			1,472
Contributed Delta Program Launch Inventory [Member] | ULA [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Maximum Potential Payments			$ 77	107
Indemnification Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of satellite missions | satellites			3
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			216	231
Carrying Amount of Liabilities			5	5
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			29	30
Carrying Amount of Liabilities			$ 2	$ 2
Guarantor Obligations, Term			P4Y0M
Maximum [Member] | Indemnification Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Loss Contingency, Estimate of Possible Loss			$ 277