XML 48 R39.htm IDEA: XBRL DOCUMENT v3.23.2
Stock-Based Compensation - Valuation (Details) - Employee Stock Option
3 Months Ended 6 Months Ended
Jun. 30, 2023
Jun. 30, 2022
Jun. 30, 2023
Jun. 30, 2022
Black-Scholes option with following assumptions:        
Expected stock price volatility (as a percent) 92.00%   92.00%  
Expected stock price volatility, minimum (as a percent)   90.00%   90.00%
Expected stock price volatility, maximum (as a percent)   91.00%   97.00%
Expected option term 6 years 6 years 6 years 6 years
Risk-free interest rate, minimum (as a percent) 3.50% 2.70% 3.50% 1.70%
Risk-free interest rate, maximum (as a percent) 3.90% 3.60% 4.00% 3.60%
Expected dividend yield (as a percent) 0.00% 0.00% 0.00% 0.00%