EQUITY-BASED COMPENSATION - Weighted Average Discounts (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
2007 Omnibus Equity Incentive Plan, Plan Grants        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Discount for the lack of distributions until vested 8.20% 26.10% 10.10% 26.20%
Marketability discount for transfer restrictions 5.80% 3.80% 5.80% 3.90%
2007 Omnibus Equity Incentive Plan, Bonus Grants        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Marketability discount for transfer restrictions 3.00% 2.30% 3.40% 2.20%