Arrangements With Off-Balance Sheet Risk (Narrative) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended															9 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Sep. 30, 2014 satellites	Sep. 30, 2014 ULA [Member]	Sep. 30, 2014 Contributed Delta Program Launch Inventory [Member] ULA [Member]	Dec. 31, 2013 Contributed Delta Program Launch Inventory [Member] ULA [Member]	Sep. 30, 2014 Indemnification Agreement [Member] satellites	Sep. 30, 2014 Indemnification Agreement [Member] Indemnification Payment [Member]	Sep. 30, 2014 Indemnification Agreement [Member] Boeing Portion Of Additional Contract Losses [Member]	Sep. 30, 2014 Other Delta Contracts [Member] Deferred support costs [Member]	Sep. 30, 2014 Other Delta Contracts [Member] ULA [Member]	Dec. 31, 2013 Other Delta Contracts [Member] ULA [Member]	Sep. 30, 2014 Deferred Support and Production Costs [Member]	Sep. 30, 2014 Other Indemnifications [Member]	Dec. 31, 2013 Other Indemnifications [Member]	Sep. 30, 2014 Credit Guarantee [Member]	Dec. 31, 2013 Credit Guarantee [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				1,239
Maximum Potential Payments					121	127				85	150	227		85	106	30	35
Advance payments received for contributed inventories				1,560
Revenues and cost of sales recorded under inventory supply agreement				1,230
Maximum exposure to loss							278	261	17
Number of satellite missions			4				3
Additional potentially unrecoverable deferred production costs	114	271
Loss Contingency, Estimate of Possible Loss													317
Carrying Amount of Liabilities												$ 8		$ 28	$ 28	$ 2	$ 2
Guarantor Obligations, Term																7