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

Stock-based Compensation - Schedule of Assumptions Used in Black-Scholes Valuation Model to Estimate Fair Value of Stock Options (Detail)

v3.21.1
Stock-based Compensation - Schedule of Assumptions Used in Black-Scholes Valuation Model to Estimate Fair Value of Stock Options (Detail)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Payment Arrangement [Abstract]    
Weighted-average risk-free interest rate 0.32% 1.79%
Expected dividend yield 0.00% 0.00%
Expected volatility 87.63% 71.84%
Expected terms 4 years 5 months 9 days 4 years 1 month 20 days