Research and Development (Details) (USD $)			3 Months Ended				6 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]		Jun. 30, 2012 COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]		Jun. 30, 2013 COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]		Jun. 30, 2012 COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]		Jun. 30, 2013 Antares Development Program [Member]	Jun. 30, 2012 Antares Development Program [Member]	Jun. 30, 2013 Antares Development Program [Member]	Jun. 30, 2012 Antares Development Program [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			532,000,000				532,000,000
Deferred revenue and customer advances	29,469,000	62,098,000
Research and development costs incurred			13,600,000	[1]	11,100,000	[1]	31,500,000	[1]	32,300,000	[1]
Less amounts funded by NASA			(1,300,000)		(4,500,000)		(3,800,000)		(15,500,000)
Net research and development expenses			12,300,000		6,600,000		27,700,000		16,800,000
Research and development costs incurred, inception to date			512,000,000				512,000,000
Less amounts funded by NASA, inception to date			(286,000,000)	[2]			(286,000,000)	[2]
Net research and development expenses, inception to date			226,000,000				226,000,000
Cash Received From NASA			281,000,000				281,000,000
Receivable From NASA			5,000,000				5,000,000
Research and development expenses											4,400,000	8,100,000	12,300,000	19,700,000
Research and development expenses incurred to date											$ 247,200,000		$ 247,200,000

[1] Includes associated general and administrative expenses.

[2] Through June 30, 2013, the company has received $281 million in cash from NASA and as of June 30, 2013, the company recorded an approximately $5 million receivable due from NASA.