Long-Term Debt - Interest Expense and Amortization of Debt Issuance Costs (Details) - USD ($) $ in Thousands  | 
3 Months Ended | |
|---|---|---|
Mar. 31, 2016  | 
Mar. 31, 2015  | 
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| Interest expense and amortization of debt issuance costs [Abstract] | ||
| Interest expense | $ 1,002 | $ 1,115 | 
| Hercules Loan [Member] | ||
| Interest expense and amortization of debt issuance costs [Abstract] | ||
| Interest expense | 672 | 234 | 
| Servier Loan [Member] | ||
| Interest expense and amortization of debt issuance costs [Abstract] | ||
| Interest expense | 226 | 255 | 
| GECC Term Loan [Member] | ||
| Interest expense and amortization of debt issuance costs [Abstract] | ||
| Interest expense | 548 | |
| Novartis Note [Member] | ||
| Interest expense and amortization of debt issuance costs [Abstract] | ||
| Interest expense | 97 | $ 78 | 
| Other [Member] | ||
| Interest expense and amortization of debt issuance costs [Abstract] | ||
| Interest expense | $ 7 | |
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- References No definition available. 
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- Definition Amount of the cost of borrowed funds accounted for as interest expense for debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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