EQUITY-BASED COMPENSATION - Summary of Non-vested restricted stock award activity (Details 4) (Non-vested restricted stock, USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Non-vested restricted stock
 
Shares  
Outstanding, as of December 31, 2012 54
Granted 212
Vested (54)
Forfeited (22)
Outstanding, as of December 31, 2013 190
Weighted Average Grant Date Fair Value  
Outstanding, as of December 31, 2012 $ 8.92
Granted $ 12.14
Vested $ 8.92
Forfeited $ 12.55
Outstanding, as of December 31, 2013 $ 12.09