XML 83 R40.htm IDEA: XBRL DOCUMENT v3.22.2.2
Stock-Based Compensation - Fair Value of Stock Options Granted Using Black-Scholes Option Pricing Model (Details) - $ / shares
9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Share-Based Payment Arrangement [Abstract]    
Expected life (in years) 5 years 6 months 25 days 5 years 6 months
Risk-free interest rate, minimum 1.70% 0.56%
Risk-free interest rate, maximum 3.30% 1.01%
Expected volatility, minimum 83.60% 80.00%
Expected volatility, maximum 90.50% 81.30%
Expected dividend yield 0.00% 0.00%
Weighted average grant-date fair value per stock option (in dollars per share) $ 0.48 $ 2.42