EQUITY-BASED COMPENSATION - Summary of stock options and SARs (Details 2) - Stock Option And Stock Appreciation Rights - USD ($) shares in Thousands, $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Total shares, Outstanding | 1,649 | 1,529 |
| Aggregate intrinsic value, Outstanding | $ 562 | |
| Weighted-average remaining contractual term (years), Outstanding | 7 years 10 months 24 days | |
| Total shares, Exercisable | 453 | |
| Aggregate intrinsic value, Exercisable | $ 562 | |
| Weighted-average remaining contractual term (years), Exercisable | 4 years 7 months 6 days |