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Stock Option Plan and Stock-based Compensation - Significant Assumptions (Details) - Options - $ / shares
3 Months Ended
Mar. 31, 2022
Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility, minimum 109.00% 92.00%
Expected volatility, maximum 110.00% 94.20%
Expected dividend rate 0.00% 0.00%
Risk free interest rate, minimum 1.73% 0.53%
Risk free interest rate, maximum 2.42% 0.73%
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years) 5 years 9 months 18 days 5 years 6 months
Stock price (in dollars per share) $ 3.78 $ 7.56
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years) 6 years 1 month 6 days 6 years 7 months 6 days
Stock price (in dollars per share) $ 4.24 $ 10.00