XML 43 R32.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation - Option Pricing Assumptions (Details)
9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected dividend yield 0.00% 0.00%
Expected term 6 years 3 months 6 years 3 months
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 66.70% 63.70%
Risk-free interest rate 1.90% 1.20%
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 68.30% 67.70%
Risk-free interest rate 2.30% 2.10%