DERIVATIVE INSTRUMENTS - FAIR VALUE OF WARRANTS (Details) - Warrants |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Fair value of warrants | |||
| Risk-free interest rate (as a percent) | 1.20% | 0.65% | 1.47% |
| Expected dividend yield (as a percent) | 0.00% | 0.00% | 0.00% |
| Expected term (in years) | 2 years 4 months 24 days | 3 years 4 months 24 days | 4 years 4 months 24 days |
| Expected volatility (as a percent) | 89.00% | 100.00% | 119.00% |