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Stock-based Compensation - Assumptions (Details) - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term 6 years 3 months  
Weighted-average grant date fair value per stock option granted $ 0.23 $ 0.28
Dividend yield 0.00% 0.00%
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term   6 years 3 months
Risk-free interest rate 1.40% 3.00%
Expected volatility 46.40% 37.90%
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term   2 years 3 months
Risk-free interest rate 0.40% 1.10%
Expected volatility 43.50% 32.30%