STOCKHOLDERS' EQUITY (DEFICIT) - Warrants (Details) - $ / shares |
12 Months Ended | |
|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Class of Warrant or Right [Line Items] | ||
| Term of warrants | 10 years | |
| Number of warrants exercised (in shares) | 0 | 0 |
| Minimum | ||
| Class of Warrant or Right [Line Items] | ||
| Warrants exercise price (in dollars per share) | $ 26.27 | |
| Maximum | ||
| Class of Warrant or Right [Line Items] | ||
| Warrants exercise price (in dollars per share) | $ 30.97 | |
| Common Stock | ||
| Class of Warrant or Right [Line Items] | ||
| Number of common stock called by warrants (in shares) | 44,101 |