Fair Value of Financial Instruments - Rollforward of Level 3 (Details) - Significant Unobservable Inputs (Level 3) - Warrant Liability - USD ($) $ in Thousands |
9 Months Ended | |
|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||
| Beginning balance | $ 1,467 | $ 3,372 |
| Change in fair value of warrant liability included in earnings | 187 | (1,473) |
| Ending balance | $ 1,654 | $ 1,899 |