v3.7.0.1
STOCK-BASED COMPENSATION - Valuation Assumptions (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Employee Stock Option        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected term (in years)   5 years 9 months 7 days   5 years 9 months 11 days
Expected volatility   55.11%   55.16%
Risk free interest rate   1.50%   1.50%
Market-Based Restricted Stock Unit [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility 46.36% 53.00% 46.36% 53.00%
Risk free interest rate 1.45% 1.07% 1.45% 1.07%
ESPP        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility, minimum 34.00% 35.00% 34.00% 35.00%
Expected volatility, maximum 39.00% 55.30% 39.00% 55.30%
Risk free interest rate, minimum 0.60% 0.07% 0.60% 0.07%
Risk free interest rate, maximum 1.07% 0.51% 1.07% 0.51%
ESPP | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected term (in years) 6 months 6 months 6 months 6 months
ESPP | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected term (in years) 1 year 2 years 1 year 2 years