Fair Value Measurements - Valuation Technique (Details) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Minimum | ||
| Valuation technique for assets measured and recorded at fair value | ||
| Risk-free interest rate (as a percent) | 0.87% | 0.50% |
| Volatility (as a percent) | 49.00% | 79.82% |
| Expected average term | 1 year 1 month 21 days | 5 months 1 day |
| Maximum | ||
| Valuation technique for assets measured and recorded at fair value | ||
| Risk-free interest rate (as a percent) | 1.96% | 1.28% |
| Volatility (as a percent) | 103.41% | 128.35% |
| Expected average term | 5 years 5 months 19 days | 3 years 15 days |