v3.6.0.2
STOCK-BASED COMPENSATION - Restricted Stock Units (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Restricted Stock Units, Weighted Average Grant Date Fair Value [Abstract]      
Aggregate grant date fair value $ 3,000 $ 6,000 $ 6,200
Payment for shares withheld for tax withholdings on vesting of restricted stock units $ (1,121) $ (3,158) $ (316)
Performance-Based Restricted Stock Unit, Conversion Ratio 100.00%    
Market-Based Restricted Stock Unit, Conversion Ratio 100.00%    
Common Stock      
Restricted Stock Units, Weighted Average Grant Date Fair Value [Abstract]      
Shares repurchased for tax withholdings on vesting of RSUs (188,984) (523,366) (65,221)
2014 Equity Incentive Plan      
Restricted Stock Units, Number of Shares [Roll Forward]      
Awards granted 3,286,825    
Awards canceled (1,056,460)    
Restricted Stock Units (RSUs) | 2014 Equity Incentive Plan      
Restricted Stock Units, Number of Shares [Roll Forward]      
Beginning balance 4,046,106    
Awards granted 3,286,825    
Awards vested (2,099,785)    
Awards canceled (867,476)    
Ending balance 4,365,670 4,046,106  
Restricted Stock Units, Weighted Average Grant Date Fair Value [Abstract]      
Beginning balance (in dollars per share) $ 6.49    
Awards granted (in dollars per share) 6.20 $ 6.45 $ 7.16
Awards vested (in dollars per share) 6.54    
Awards canceled (in dollars per share) 6.57    
Ending balance (in dollars per share) $ 6.23 $ 6.49  
Aggregate grant date fair value $ 20,400 $ 21,400 $ 23,500
Fair value of shares vested $ 12,500 $ 9,600 $ 900
Restricted Stock Units (RSUs) | Vesting period, one year      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Restricted Stock Units (RSUs) | Vesting period, four years      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 4 years    
Performace-Based Restricted Stock Unit [Member]      
Restricted Stock Units, Number of Shares [Roll Forward]      
Awards granted 222,875    
Market-Based Restricted Stock Unit      
Restricted Stock Units, Number of Shares [Roll Forward]      
Awards granted 404,000