Annual report pursuant to Section 13 and 15(d)

Stock Plans and Stock-Based Compensation - Estimated Weighted-Average Grant Date Fair Value (Detail)

v3.21.1
Stock Plans and Stock-Based Compensation - Estimated Weighted-Average Grant Date Fair Value (Detail) - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term 6 years 1 month 6 days 6 years 2 months 12 days
Expected volatility 105.00% 76.00%
Risk-free interest rate 0.40% 2.10%
Expected dividend yield 0.00%  
Weighted-average grant date fair value per share $ 3.91 $ 5.60