v3.20.4
Shareholders' Equity - Fair Value Assumptions of Stock Options Granted to Employees (Details) - Employee Stock Options
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 46.40% 50.70%
Risk-free interest rate 1.04% 2.25%
Dividend yield 0.00% 0.00%
Average expected life 4 years 4 months 28 days 4 years 9 months 7 days