Annual report pursuant to Section 13 and 15(d)

Significant Accounting Policies (Narrative) (Details)

v3.19.2
Significant Accounting Policies (Narrative) (Details) - USD ($)
12 Months Ended
Apr. 30, 2019
Apr. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Cash equivalents
Cash insured by FDIC 250,000 250,000
Amount of cash balance uninsured by FDIC 9,359,208 14,422,499
Marketing and promotional costs 9,096,550 5,428,828
Long term accounts receivable 3,085,243 1,315,050
Restricted cash 448,400 $ 190,506
Letter of credit issued by bank $ 71,828  
Employee Stock Option [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities 3,409,154 2,980,010
Warrant [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities 731,152 651,286
Unvested Restricted Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities 64,116 0
Convertible Debt [Member] [Default Label]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities 4,167 4,167
Convertible debt $ 50,000 $ 50,000
Sales Revenue, Net [Member] | Non-US [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Percentage of revenues from students outside the United States 1.62% 2.30%
Letter of Credit [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Restricted cash $ 120,864  
Letter of credit issued by bank $ 255,708