Research and Development (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue and customer advances	$ 77,331,000				$ 77,331,000				$ 104,970,000
Research and development expenses	32,913,000		26,681,000		82,721,000		67,248,000
COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Aggregate cash milestone payments to partially fund project costs	288,000,000				288,000,000
Estimated total project costs	495,000,000				495,000,000
Deferred revenue and customer advances	0				0				6,200,000
Research and development costs incurred	21,200,000	[1]	36,800,000	[1]	53,500,000	[1]	115,100,000	[1]
Less amounts funded by NASA	(6,000,000)		(23,000,000)		(21,500,000)		(82,300,000)
Net research and development expenses	15,200,000		13,800,000		32,000,000		32,800,000
Research and development costs incurred, inception to date	471,400,000	[1]			471,400,000	[1]
Less amounts funded by NASA, inception to date	(281,800,000)				(281,800,000)
Net research and development expenses, inception to date	189,600,000				189,600,000
Antares Development Program [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expenses	9,900,000		9,000,000		29,600,000		24,200,000
Research and development expenses incurred to date	$ 221,900,000				$ 221,900,000

[1] Includes general and administrative expenses.