Research and Development (Details) (USD $)
3 Months Ended9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Sep. 30, 2011
Sep. 30, 2010
Dec. 31, 2010
Research and Development [Abstract]     
Research and development expenses$ 26,681,000$ 35,367,000$ 67,248,000$ 95,798,000 
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 costs288,000,000 288,000,000  
Estimated total project costs458,000,000 458,000,000  
Deferred revenue and customer advances26,900,000 26,900,000 25,200,000
Research and development costs incurred36,800,00039,900,000115,100,000107,000,000 
Less - amounts funded by NASA23,000,00019,000,00082,300,00052,100,000 
Net research and development expenses13,800,00020,900,00032,800,00054,900,000 
Research and development costs incurred, inception to date374,300,000 374,300,000  
Less - amounts funded by NASA, inception to date234,600,000 234,600,000  
Net research and development expenses, inception to date139,700,000 139,700,000  
Taurus II Development Program [Member]
     
Research and Development [Abstract]     
Research and development expenses$ 9,000,000$ 12,300,000$ 24,200,000$ 35,400,000