Research and Development (Details) (USD $)	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Dec. 31, 2011
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Deferred revenue and customer advances	$ 126,298,000				$ 104,970,000
Research and development expenses	27,878,000		17,135,000
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
Estimated total project costs	472,000,000
Deferred revenue and customer advances	0				6,200,000
Research and development costs incurred	21,200,000	[1]	42,000,000	[1]
Less amounts funded by NASA	(11,000,000)		(34,100,000)
Net research and development expenses	10,200,000		7,900,000
Research and development costs incurred, inception to date	439,100,000	[1]
Less amounts funded by NASA, inception to date	(271,300,000)
Net research and development expenses, inception to date	167,800,000
Antares Development Program [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expenses	11,600,000		7,100,000
Research and development expenses incurred to date	$ 203,800,000

[1] Includes associated general and administrative expenses.