v3.8.0.1
STOCK-BASED COMPENSATION - Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Jan. 01, 2017
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Payments Related to Tax Withholding for Share-based Compensation   $ 600 $ 400 $ 1,070 $ 941  
Shares Available for Grant            
Options granted (shares)       0    
Options canceled (shares)       1,436,112    
Number of Shares            
Beginning balance (shares) 6,219,774     6,219,774    
Options granted (shares)       0    
Options exercised (shares)       (409,065)    
Options forfeited (shares)       (1,436,112)    
Ending balance (shares)   4,374,597   4,374,597   6,219,774
Options Exercisable (shares)   3,439,751   3,439,751    
Weighted Average Exercise Price            
Beginning balance (in dollars per share) $ 6.15     $ 6.15    
Options granted (in dollars per share)       0.00    
Options exercised (in dollars per share)       1.73    
Options forfeited (in dollars per share)       7.74    
Ending balance (in dollars per share)   $ 6.04   6.04   $ 6.15
Options exercisable (in dollars per share)   $ 5.81   $ 5.81    
Weighted Average Remaining Contractual Life            
Weighted average remaining contractual life, period start       6 years 26 days   6 years 5 months 1 day
Weighted average remaining contractual life, period end       6 years 26 days   6 years 5 months 1 day
Weighted average life, options exercisable       5 years 6 months 26 days    
Aggregate Intrinsic Value            
Aggregate intrinsic value, period start $ 6,056     $ 6,056    
Aggregate intrinsic value, period end   $ 2,732   2,732   $ 6,056
Aggregate intrinsic value, options exercisable   2,732   2,732    
Weighted average grant date fair value per share of stock options (in dollars per share)     $ 3.03   $ 3.15  
Aggregate grant date fair value     $ 100   $ 3,000  
Total intrinsic value of options exercised   0 900 1,200 1,600  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value   $ 700 $ 1,400 $ 2,600 $ 5,900  
2014 Equity Incentive Plan            
Shares Available for Grant            
Beginning balance (shares) 5,116,753     5,116,753    
Authorized (shares) 2,612,263     2,612,263    
Options granted (shares)       0    
Options canceled (shares)       1,436,112    
Awards granted (shares)       (3,287,665)    
Awards canceled (shares)       1,595,966    
Ending balance (shares)   7,473,429   7,473,429   5,116,753
Number of Shares            
Options granted (shares)       0    
Options forfeited (shares)       (1,436,112)