EQUITY-BASED COMPENSATION - Summary of stock option and SAR activity (Details 1) (Stock Option And Stock Appreciation Rights, USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Stock Option And Stock Appreciation Rights
     
Shares      
Outstanding, January 1, 2013 1,662    
Granted 478    
Exercised (433) (638) (205)
Forfeited or expired (270)    
Outstanding, at December 31, 2013 1,437 1,662  
Exercisable at December 31, 2013 722    
Weighted Average Exercise Price      
Outstanding, January 1, 2013 $ 6.37    
Granted $ 11.19    
Exercised $ 5.90    
Forfeited or expired $ 8.32    
Outstanding, at December 31, 2013 $ 7.77 $ 6.37  
Exercisable at December 31, 2013 $ 6.86