Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Assumptions Used (Details)

v3.20.4
Stock-based Compensation - Assumptions Used (Details)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Stock options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected life (years) 5 years 3 months 18 days 5 years 7 months 6 days 5 years 7 months 6 days
Volatility 50.40% 55.30% 60.00%
Risk-free interest rate 1.00% 2.40% 2.70%
Expected dividend yield 0.00% 0.00% 0.00%
Nonemployee Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected life (years) 5 years 4 months 24 days    
Volatility 51.60%    
Risk-free interest rate 0.40%    
Expected dividend yield 0.00%    
PBOs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected life (years) 5 years 3 months 18 days 5 years 7 months 6 days 5 years 7 months 6 days
Volatility 49.90% 55.80% 60.30%
Risk-free interest rate 1.30% 2.50% 2.70%
Expected dividend yield 0.00% 0.00% 0.00%