Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Fair Value of Each Stock Award for Employees and Directors (Detail)

v3.21.2
Common Stock - Summary of Fair Value of Each Stock Award for Employees and Directors (Detail)
9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Risk-free interest rates 0.64% 1.43%
Expected dividend yield 0.00% 0.00%
Expected life 5 years 11 months 26 days 5 years 11 months 23 days
Expected volatility 109.61% 104.64%