CONVERTIBLE PREFERRED STOCK AND WARRANTS - RECONCILIATION OF CHANGES IN FAIR VALUE OF WARRANTS (Details) - Warrant - Placement Agent Warrant $ in Thousands |
12 Months Ended |
|---|---|
|
Dec. 31, 2016
USD ($)
| |
| Class of Stock [Line Items] | |
| Beginning balance | $ 267 |
| Exercise of warrants | (698) |
| Change in fair value | 634 |
| Ending balance | $ 203 |