Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Schedule of All Options and Exercisable Options (Details)

v3.20.2
Stockholders' Equity - Schedule of All Options and Exercisable Options (Details) - $ / shares
12 Months Ended
Apr. 30, 2020
Apr. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Outstanding No. of Options 2,734,899 3,408,154
EXERCISABLE OPTIONS, Exercisable No. of Options 1,742,599  
$1.57 to $2.10    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 1.57  
ALL OPTIONS, Exercise Price Upper Range 2.10  
ALL OPTIONS, Weighted Average Exercise Price $ 2.00  
ALL OPTIONS, Outstanding No. of Options 561,724  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 2.00  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 8 months 15 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 561,724  
$2.28 to $2.76    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 2.28  
ALL OPTIONS, Exercise Price Upper Range 2.76  
ALL OPTIONS, Weighted Average Exercise Price $ 2.30  
ALL OPTIONS, Outstanding No. of Options 374,446  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 2.30  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 4 months 28 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 374,446  
$3.24 to $4.38    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 3.24  
ALL OPTIONS, Exercise Price Upper Range 4.38  
ALL OPTIONS, Weighted Average Exercise Price $ 3.89  
ALL OPTIONS, Outstanding No. of Options 327,730  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 3.87  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 1 year 7 months 6 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 275,063  
$4.50 to $5.20    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 4.50  
ALL OPTIONS, Exercise Price Upper Range 5.20  
ALL OPTIONS, Weighted Average Exercise Price $ 4.94  
ALL OPTIONS, Outstanding No. of Options 677,277  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 4.94  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 2 years 6 months 14 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 226,125  
$5.95 to $6.28    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 5.95  
ALL OPTIONS, Exercise Price Upper Range 6.28  
ALL OPTIONS, Weighted Average Exercise Price $ 6.07  
ALL OPTIONS, Outstanding No. of Options 79,917  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 6.07  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 2 years 2 months 12 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 26,639  
$7.17 to $7.55    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 7.17  
ALL OPTIONS, Exercise Price Upper Range 7.55  
ALL OPTIONS, Weighted Average Exercise Price $ 7.41  
ALL OPTIONS, Outstanding No. of Options 549,639  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 7.32  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 3 years 6 months 29 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 223,880  
$8.57 to $9.07    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
ALL OPTIONS, Exercise Price Lower Range $ 8.57  
ALL OPTIONS, Exercise Price Upper Range 9.07  
ALL OPTIONS, Weighted Average Exercise Price $ 8.97  
ALL OPTIONS, Outstanding No. of Options 164,166  
EXERCISABLE OPTIONS, Weighted Average Exercise Price $ 8.97  
EXERCISABLE OPTIONS, Weighted Average Remaining Life In Years 2 years 8 months 8 days  
EXERCISABLE OPTIONS, Exercisable No. of Options 54,722