Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans and Stock Based Compensation - Weighted-Average Fair Value Valuation Assumptions (Detail)

v3.20.4
Equity Incentive Plans and Stock Based Compensation - Weighted-Average Fair Value Valuation Assumptions (Detail) - Employee Stock Options - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Risk-free interest rate 1.44% 2.37%
Expected term (in years) 6 years 29 days 6 years 29 days
Dividend yield 0.00% 0.00%
Volatility 110.90% 108.70%
Weighted-average fair value of stock options granted $ 11.75 $ 5.00