Quarterly report pursuant to Section 13 or 15(d)

Significant Accounting Policies (Narrative) (Details)

v3.19.2
Significant Accounting Policies (Narrative) (Details) - USD ($)
3 Months Ended
Jul. 31, 2019
Jul. 31, 2018
Apr. 30, 2019
Cash equivalents  
Cash insured by FDIC 250,000   250,000
Amount of cash balance uninsured by FDIC 7,323,630   9,359,208
Marketing and promotional costs 2,209,239 $ 2,187,456  
Long term accounts receivable 4,249,969   3,085,243
Restricted cash 452,021   448,400
Letter of credit issued by bank 71,932    
Right of use lease asset 7,996,585  
Right of use lease liability $ 7,095,695  
Employee Stock Option [Member]      
Antidilutive securities 3,237,840 3,515,070  
Warrant [Member]      
Antidilutive securities 687,292 650,847  
Unvested Restricted Stock [Member]      
Antidilutive securities 99,803 0  
Convertible Debt [Member] [Default Label]      
Antidilutive securities 4,167 4,167  
Convertible debt $ 50,000 $ 50,000  
Sales Revenue, Net [Member] | Non-US [Member]      
Percentage of revenues from students outside the United States 1.48% 1.90%  
Letter of Credit [Member]      
Restricted cash $ 122,262    
Letter of credit issued by bank $ 257,827