STOCKHOLDERS' EQUITY - Common Stock Held in Escrow in Connection with Merger (Details) - Merger agreement - shares |
6 Months Ended | |
|---|---|---|
May 23, 2016 |
Jun. 30, 2017 |
|
| Business Acquisition [Line Items] | ||
| Number of common stock shares deposited in escrow (in shares) | 4,041 | |
| Contingent pending conversion or exercise of derivative securities | ||
| Business Acquisition [Line Items] | ||
| Number of common stock shares deposited in escrow (in shares) | 200 |