Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summary of Warrant Activity (Details)

v3.20.2
Stockholders' Equity - Summary of Warrant Activity (Details) - Warrant - USD ($)
 3 Months Ended
Jul. 31, 2020
Apr. 30, 2020
Jul. 31, 2020
Number of Shares      
Balance Outstanding, April 30, 2020 (in shares)     566,223
Granted (in shares)     0
Warrants exercised (in shares)     (192,049)
Surrendered (in shares)     0
Expired (in shares)     0
Balance Outstanding, July 31, 2020 (in shares) 374,174 566,223 374,174
Exercisable, July 31, 2020 (in shares) 374,174   374,174
Weighted Average Exercise Price      
Balance Outstanding, April 30, 2020 (in dollars per share)     $ 6.22
Granted (in dollars per share)     0
Exercised (in dollars per share)     5.60
Surrendered (in dollars per share)     0
Expired (in dollars per share)     0
Balance Outstanding, July 31, 2020 (in dollars per share) $ 6.37 $ 6.22 6.37
Exercisable, July 31, 2020 (in dollars per share) $ 6.37   $ 6.37
Weighted Average Remaining Contractual Term      
Weighted Average Remaining Contractual Term 2 years 7 months 20 days 3 years 2 months 1 day  
Weighted Average Remaining Contractual Term, Exercisable 2 years 7 months 20 days    
Aggregate Intrinsic Value      
Average Intrinsic Value $ 908,156 $ 950,100 $ 908,156
Aggregate Intrinsic Value, Exercisable $ 908,156   $ 908,156