Arrangements With Off-Balance Sheet Risk (Narrative) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended
	Dec. 31, 2011	Jun. 30, 2011	Mar. 31, 2013 satellites	Mar. 31, 2013 ULA [Member]	Mar. 31, 2013 Contributed Delta Program Launch Inventory [Member]	Dec. 31, 2012 Contributed Delta Program Launch Inventory [Member]	Mar. 31, 2013 Indemnification Agreement [Member]	Mar. 31, 2013 Indemnification Agreement [Member] Boeing Portion Of Additional Contract Losses [Member]	Mar. 31, 2013 Indemnification Agreement [Member] Indemnification Payment [Member]	Mar. 31, 2013 Other Delta Contracts [Member]	Dec. 31, 2012 Other Delta Contracts [Member]	Mar. 31, 2013 Other Delta Contracts [Member] Deferred support costs [Member]	Mar. 31, 2013 Deferred Support and Production Costs [Member]	Mar. 31, 2013 Other Indemnifications [Member]	Dec. 31, 2012 Other Indemnifications [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 inventory supply agreement			1,860
Contributed inventories consumed by ULA			1,223
Maximum Potential Payments					137	137			261	232	232	85		128	137
Advanced payments received for contributed inventories			1,080
Revenues and cost of sales recorded under inventory supply agreement				795
Number of satellite missions			4
Maximum exposure to loss							279	18
Additional potentially unrecoverable deferred production costs	114	271
Loss Contingency, Estimate of Possible Loss													317
Carrying Amount of Liabilities										$ 8	$ 8			$ 32	$ 32