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Stock Incentive Plans - Schedule of Assumptions Used in Black-Scholes Option Pricing Model to Estimate Fair Value of Stock Options (Details) - Stock Options - Employees and Directors
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Risk-free interest rate, minimum 0.90% 0.40%
Risk-free interest rate, maximum 1.40% 1.40%
Expected volatility, minimum 93.00% 93.00%
Expected volatility, maximum 94.00% 94.00%
Minimum    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Expected term (in years) 5 years 4 months 24 days 5 years
Maximum    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Expected term (in years) 7 years 7 years