Quarterly report pursuant to Section 13 or 15(d)

Stock Option and Incentive Plans - Assumptions to Compute Fair Value of Stock Option Grants (Detail)

v3.21.2
Stock Option and Incentive Plans - Assumptions to Compute Fair Value of Stock Option Grants (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]        
Risk free interest rate 0.81% 0.27% 0.83% 1.15%
Expected dividend yield      
Expected term (in years) 6 years 1 month 13 days 6 years 1 month 13 days 5 years 11 months 26 days 6 years 10 days
Expected volatility 95.10% 97.40% 94.50% 94.60%