Quarterly report pursuant to Section 13 or 15(d)

Stock-based compensation - Stock options (Details)

v3.21.2
Stock-based compensation - Stock options (Details) - Stock Options
9 Months Ended
Oct. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting term 4 years
Term of options 10 years
Days following termination of employment or service  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expiration term 90 days
Months following an optionees' death or disability  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expiration term 12 months