Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events (Details)

v3.20.4
Subsequent Events (Details) - USD ($)
3 Months Ended 9 Months Ended
Feb. 26, 2021
Jan. 31, 2021
Jan. 31, 2021
Apr. 30, 2020
Jan. 31, 2020
Subsequent Event [Line Items]          
Vesting of outstanding shares   1,260,213 1,260,213   2,776,778
Stock Incentive Plan and Stock Option Grants to Employees and Directors          
Subsequent Event [Line Items]          
Vesting of outstanding shares       2,740,539  
Weighted-average exercise price of unvested shares (in dollars per share)   $ 6.13 $ 6.13 $ 4.62  
Restricted Stock Units (RSUs)          
Subsequent Event [Line Items]          
Vested (in shares)   131,250 206,109    
Subsequent Event | Former CFO          
Subsequent Event [Line Items]          
Severance benefits $ 150,000        
Bonus for prior fiscal year 18,563        
Bonus for current fiscal year 33,750        
Relocation costs reimbursement $ 96,250        
Subsequent Event | Former CFO | Stock Incentive Plan and Stock Option Grants to Employees and Directors          
Subsequent Event [Line Items]          
Vesting of outstanding shares 13,892        
Weighted-average exercise price of unvested shares (in dollars per share) $ 5.12        
Subsequent Event | Former CFO | Restricted Stock Units (RSUs)          
Subsequent Event [Line Items]          
Vested (in shares) 80,251