Quarterly report pursuant to Section 13 or 15(d)

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

v3.21.2
Share-based Compensation, Weighted Average Assumptions Used in Black-Scholes Option-pricing Model (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
2018 Equity Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]        
Common stock available for future issuance (in shares) 0   0  
2020 Plan Evergreen Provision [Member]        
Weighted-average Assumptions Used in Black-Scholes Option-pricing Model [Abstract]        
Expected stock price volatility 99.20% 95.50% 97.20% 95.50%
Expected life of options (years) 5 years 9 months 18 days 10 years 5 years 9 months 18 days 10 years
Expected dividend yield 0.00% 0.00% 0.00% 0.00%
Risk free interest rate 0.90% 0.70% 0.90% 0.70%
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]        
Stock options vested (in shares) 114,727 14,586 232,944 81,198
Stock options forfeited (in shares) 25,558 0 25,558 7,924
Common stock available for future issuance (in shares) 1,047,011   1,047,011  
Unrecognized share-based compensation cost $ 2.8   $ 2.8  
Weighted average period to recognized share-based compensation     1 year 3 months 18 days  
Inducement Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Abstract]        
Common stock available for future issuance (in shares) 1,047,011   1,047,011