v3.7.0.1
STOCK-BASED COMPENSATION - Valuation Assumptions (Details)
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Stock Options    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years)   5 years 10 months 20 days
Expected volatility   55.64%
Risk free interest rate   1.52%
ESPP    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility, minimum 34.00% 35.00%
Expected volatility, maximum 39.00% 55.30%
Risk free interest rate, minimum 0.60% 0.07%
Risk free interest rate, maximum 0.82% 0.51%
ESPP | Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years) 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