Arrangements With Off-Balance Sheet Risk (Narrative) (Details) $ in Millions	1 Months Ended		6 Months Ended
	Dec. 31, 2011 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2016 USD ($) satellites	Dec. 31, 2015 USD ($)
Guarantees [Line Items]
Number of satellite missions | satellites			4
Additional potentially unrecoverable deferred production costs	$ 114	$ 271
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 launch program inventories consumed by ULA			1,273
Revenues and cost of sales recorded under inventory supply agreement			1,410
Payments received under inventory supply agreement			1,740
Payments made under inventory supply agreement			63
Contributed Delta Program Launch Inventory [Member] | ULA [Member]
Guarantees [Line Items]
Maximum Potential Payments			87	$ 107
Contract Pricing [Member] | ULA [Member]
Guarantees [Line Items]
Maximum Potential Payments			261	261
Carrying Amount of Liabilities			7	7
Indemnification Agreement [Member]
Guarantees [Line Items]
Maximum exposure to loss			$ 277
Number of satellite missions | satellites			3
Other Delta Contracts [Member] | Deferred support costs [Member]
Guarantees [Line Items]
Maximum Potential Payments			$ 85
Other Delta Contracts [Member] | Deferred production costs [Member]
Guarantees [Line Items]
Maximum Potential Payments			91
Other Delta Contracts [Member] | ULA [Member]
Guarantees [Line Items]
Maximum Potential Payments			216	231
Carrying Amount of Liabilities			5	5
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			30	30
Carrying Amount of Liabilities			$ 2	$ 2
Guarantor Obligations, Term			5