Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation, Weighted Average Assumptions Used in Black-Scholes Option-pricing Model (Details)

v3.23.1
Stock-based Compensation, Weighted Average Assumptions Used in Black-Scholes Option-pricing Model (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
2020 Equity Incentive Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]    
Common stock available for future issuance (in shares) 894,920  
2018 Equity Incentive Plan [Member]    
Weighted-average Assumptions Used in Black-Scholes Option-pricing Model [Abstract]    
Expected stock price volatility 97.40% 98.10%
Expected life of options (years) 5 years 9 months 18 days 5 years 9 months 18 days
Expected dividend yield 0.00% 0.00%
Risk free interest rate 2.30% 0.90%
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]    
Stock options vested (in shares) 488,621 468,301
Weighted average fair value per share of options vesting (in dollars per share) $ 3.29 $ 3.49
Stock options forfeited (in shares) 29,788 34,220
Unrecognized stock-based compensation cost $ 2.6  
Weighted average period to recognized stock-based compensation 1 year 2 months 12 days  
Inducement Plan [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]    
Common stock available for future issuance (in shares) 894,920