Annual report pursuant to Section 13 and 15(d)

Assumptions Used in Estimating Fair Value of Stock Options Granted (Detail)

v3.22.0.1
Assumptions Used in Estimating Fair Value of Stock Options Granted (Detail) - $ / shares
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]      
Expected term (years) 6 years 1 month 6 days 5 years 6 months 6 years
Volatility 111.00% 103.00% 85.00%
Annual dividend per share $ 0 $ 0 $ 0
Risk-free interest rate 1.00% 0.40% 2.60%