Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity (Stock Options Narrative) (Details)

v3.19.1
Stockholders' Equity (Stock Options Narrative) (Details) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Dec. 13, 2018
Sep. 06, 2018
Sep. 06, 2018
Jul. 19, 2018
Dec. 24, 2018
Jan. 31, 2019
Jan. 31, 2018
Jan. 31, 2019
Jan. 31, 2018
Jul. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Unrecognized compensation cost           $ 2,671,603   $ 2,671,603    
Weighted average recognition period               3 years    
Stock-based compensation           $ 350,838 $ 162,544 $ 866,129 $ 466,468  
Share issued in exercise of stock options               49,792    
Proceeds from stock options exercised               $ 110,143 $ 598,876  
Chief Executive Officer [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted       200,000            
Options granted, exercise price       $ 7.55            
Weighted average recognition period       5 years            
Chief Academic Officer [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted       180,000            
Options granted, exercise price       $ 7.55            
Weighted average recognition period       5 years            
Chief Operating Officer [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted       180,000            
Options granted, exercise price       $ 7.55            
Weighted average recognition period       5 years            
Board of directors [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted       560,000            
Weighted average recognition period       5 years            
Fair value of stock options granted       $ 1,433,600            
Fair value of stock options per share       $ 2.56            
Chief Financial Officer [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted   180,000                
Weighted average recognition period   5 years                
Fair value of stock options granted     $ 257,400              
Options term     33 months              
Chief Accounting Officer [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted   50,000                
Weighted average recognition period   5 years                
Fair value of stock options granted     $ 71,500              
Options term     33 months              
61 Employee [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted 67,000                  
Fair value of stock options granted $ 136,000                  
Fair value of stock options per share $ 5.20                  
Options term 36 months                  
Three Directors [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted         61,667          
Fair value of stock options per share         $ 5.1445          
Director One[Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted         41,667          
Fair value of stock options per share         $ 5.1445          
Two Other Director [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Options granted         10,000          
Fair value of stock options per share         $ 5.1445          
Director [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Fair value of stock options granted         $ 123,000          
Options term         36 months          
Employee Stock Option [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Stock-based compensation               $ 866,129    
Cashless Exercise of Stock Options [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Share issued in exercise of stock options               86,635    
Cashless exercise of stock option               145,837    
Equity Incentive Plan [Member]                    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                    
Equity Incentive Plan, shares authorized                   3,500,000
Equity Incentive Plan, available shares remaining for issuance 500,000                
Shares remaining available for future issuance           65,000   65,000