Commitments and Contingencies (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Apr. 02, 2010 Spacecraft Development and Manufacturing Business [Member]
Research and development expenses [Abstract]
Research and development costs reported as allowable expenses	$ 11,600,000	$ 7,100,000
Research and development allowable costs reported as allowable expenses inception to date	165,000,000
Discussion with US Securities and Exchange Commission [Abstract]
Percentage of Commercial and Resupply Services Contract that is launch and delivery milestones	25.00%
Total revenue of Commercial Resupply Services Contract inception-to-date	703,000,000
Other Contingencies [Abstract]
Amount of cash paid to acquire certain assets and liabilities				55,000,000
Receivables	$ 420,350,000		$ 333,467,000