Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Fair Value of Stock Options Granted is Calculated Using Black Scholes Option Pricing Model with Range of Assumptions (Details)

v3.20.2
Stock-Based Compensation - Fair Value of Stock Options Granted is Calculated Using Black Scholes Option Pricing Model with Range of Assumptions (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 (years) 6 years 5 years 10 months 24 days   5 years 10 months 24 days
Expected volatility, Minimum 90.80% 80.60% 83.80% 78.70%
Expected volatility, Maximum 91.90% 81.00% 91.90% 81.90%
Risk-free interest rate 0.40%      
Risk-free interest rate, Minimum   1.50% 0.40% 1.50%
Risk-free interest rate, Maximum   1.90% 1.60% 2.60%
Minimum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term (years)     5 years  
Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Expected term (years)     6 years