Long-Term Obligation (Summary of Payment Obligations under Financing Agreement) (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Long-Term Obligation [Abstract] | ||
| Total repayment obligation | $ 45,000 | $ 45,000 |
| Less interest to be accreted in future periods | (2,385) | (5,232) |
| Less payments made | (15,087) | (5,881) |
| Less current portion | (14,965) | (9,424) |
| Long-term obligation, net of current portion | $ 12,563 | $ 24,463 |