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Stock-Based Awards - Summary of Assumptions Used for Estimating the Fair Value of Stock Options Granted (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term of options (in years)   6 years    
Expected stock price volatility   88.50%    
Expected stock price volatility,minimum 99.70%   88.80% 88.50%
Expected stock price volatility,maximum 108.60%   108.60% 89.40%
Risk-free interest rate   1.90%    
Risk-free interest rate, minimum 0.30%   0.30% 1.90%
Risk-free interest rate, maximum 0.40%   1.20% 2.50%
Minimum [Member]        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term of options (in years) 5 years   5 years 5 years 10 months 24 days
Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term of options (in years) 6 years 1 month 6 days   6 years 1 month 6 days 6 years