INCOME TAXES - Schedule of Net Operating Loss and Tax Credit Carryforwards (Details) $ in Thousands |
Dec. 31, 2016
USD ($)
|
|---|---|
| Federal | |
| Operating Loss and Tax Credit Carryforwards [Line Items] | |
| Net operating losses | $ 115,331 |
| State | |
| Operating Loss and Tax Credit Carryforwards [Line Items] | |
| Net operating losses | 79,084 |
| Research and Development | Federal | |
| Operating Loss and Tax Credit Carryforwards [Line Items] | |
| Tax credits | 5,816 |
| Research and Development | State | |
| Operating Loss and Tax Credit Carryforwards [Line Items] | |
| Tax credits | $ 6,712 |