Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Assumptions (Details)

v3.10.0.1
Stockholders' Equity - Assumptions (Details)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate (as a percent) 2.70% 2.00% 1.30%
Expected volatility (as a percent) 33.00% 43.00% 48.00%
Expected term 5 years 1 month 6 days 6 years 6 months 6 years 7 months 6 days
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate (as a percent) 3.00% 2.20% 1.90%
Expected volatility (as a percent) 36.00% 47.00% 50.00%
Expected term 5 years 9 months 18 days 6 years 9 months 18 days 6 years 8 months 12 days