SEGMENT AND GEOGRAPHICAL CONCENTRATION - Revenues by Geographic Area (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Segment Reporting Information [Line Items] | ||||
| Revenue | $ 59,310 | $ 55,009 | $ 174,843 | $ 161,787 |
| Sales Revenue, Net | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 59,310 | 55,009 | 174,843 | 161,787 |
| United States | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 45,978 | 39,459 | 133,409 | 116,055 |
| United States | Sales Revenue, Net | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | 45,978 | 39,459 | 133,409 | 116,055 |
| International | Sales Revenue, Net | ||||
| Segment Reporting Information [Line Items] | ||||
| Revenue | $ 13,332 | $ 15,550 | $ 41,434 | $ 45,732 |