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Stock-based Compensation - Fair Value Assumptions (Details) - Stock options
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Weighted average expected term 6 years 1 month 6 days 6 years 1 month 6 days
Risk-free interest rate 0.70% 1.30%
Volatility 50.00% 40.00%
Expected dividend yield 0.00% 0.00%