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Stock-Based Compensation - Estimated Fair Value of Option on Grant Date using Weighted Average Assumptions (Details) - Employee Stock Option - $ / shares
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 0.88% 1.37%
Expected term (in years) 6 years 6 years
Expected volatility 72.00% 71.00%
Expected dividend yield 0.00% 0.00%
Fair value of common stock (in usd per share) $ 3.91 $ 5.09