General form of registration statement for all companies including face-amount certificate companies

Share-Based Payment and Related Stock Option Plan - Summary of Share-based Payments to be a Level 3 Fair Value Measurement (Detail)

v3.21.2
Share-Based Payment and Related Stock Option Plan - Summary of Share-based Payments to be a Level 3 Fair Value Measurement (Detail)
9 Months Ended 12 Months Ended
Sep. 30, 2020
Dec. 31, 2020
Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Line Items]      
Risk-free interest rate   1.58%  
Expected term (life) of options (in years)   2 years  
Expected dividends 0.00% 0.00% 0.00%
Expected volatility   86.30%  
Maximum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Line Items]      
Risk-free interest rate 2.47%   2.47%
Expected term (life) of options (in years) 4 years   4 years
Expected volatility 86.30%   86.30%
Minimum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Line Items]      
Risk-free interest rate 1.58%   1.58%
Expected term (life) of options (in years) 2 years   2 years
Expected volatility 67.90%   67.90%