Annual report pursuant to Section 13 and 15(d)

Stock Based Compensation - Stock-based Compensation Assumptions (Details)

v3.20.4
Stock Based Compensation - Stock-based Compensation Assumptions (Details)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term of options (in years)     5 years 6 months
Expected annual dividend yield 0.00%    
Service Based Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected stock price volatility   55.00%  
Expected annual dividend yield 0.00% 0.00%  
Service Based Options | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate 0.19% 1.47%  
Expected term of options (in years) 1 year 9 months 5 years  
Expected stock price volatility 70.00%    
Service Based Options | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate 1.48% 2.59%  
Expected term of options (in years) 6 years 3 months 6 years 3 months  
Expected stock price volatility 79.00%    
Market Based Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate 0.30% 2.32%  
Expected term of options (in years)   10 years  
Expected stock price volatility 80.00% 60.00%  
Expected annual dividend yield 0.00% 0.00%  
Market Based Options | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term of options (in years) 4 years 3 months 18 days    
Market Based Options | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate 0.34%    
Expected term of options (in years) 5 years