Annual report pursuant to Section 13 and 15(d)

Subsequent Events - Additional Information (Detail)

v3.19.2
Subsequent Events - Additional Information (Detail) - USD ($)
1 Months Ended 2 Months Ended 12 Months Ended
Jul. 15, 2019
Jun. 12, 2019
Jun. 11, 2019
Jul. 24, 2019
Jun. 18, 2019
Jun. 16, 2019
Jul. 26, 2019
May 31, 2019
May 31, 2018
May 31, 2017
Jul. 31, 2019
May 14, 2019
Subsequent Event [Line Items]                        
Warrants to purchase common shares, shares             1,984,769          
Share Price                       $ 0.40
Percentage of Shares Issuable Upon Exercise Of Original Warrants                       50.00%
Proceeds From Exercise Of Warrants               $ 0 $ 3,161,131 $ 397,883    
DrScottA Kelly [Member]                        
Subsequent Event [Line Items]                        
Related Party Cost Payable In Cash Periodically   $ 50,000                    
DrKelly [Member] | Consulting Agreement [Member]                        
Subsequent Event [Line Items]                        
Related Party Cost Payable In Cash Periodically $ 20,000                      
DrWelch [Member] | Consulting Agreement [Member]                        
Subsequent Event [Line Items]                        
Related Party Cost Payable In Cash Periodically $ 20,000                      
Subsequent Event                        
Subsequent Event [Line Items]                        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized     75,000   100,000 25,000            
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price     $ 0.43   $ 0.52 $ 0.44            
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period     10 years   10 years 10 years            
Proceeds From Exercise Of Warrants   8,300,000   $ 2,500,000                
Placement agent fees and expenses   $ 800,000   $ 237,000                
Subsequent Event | Carl C Dockery [Member]                        
Subsequent Event [Line Items]                        
Warrants to purchase common shares, shares   1,425,000                    
Subsequent Event | Additional Shares [Member]                        
Subsequent Event [Line Items]                        
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized         50,000              
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price         $ 0.90              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period         10 years              
Subsequent Event | Additional Shares [Member] | DrScottA Kelly [Member]                        
Subsequent Event [Line Items]                        
Warrants to purchase common shares, shares   25,000                    
Subsequent Event | Additional Shares [Member] | Carl C Dockery [Member]                        
Subsequent Event [Line Items]                        
Warrants to purchase common shares, shares   712,500                    
Subsequent Event | Convertible Notes Payable                        
Subsequent Event [Line Items]                        
Outstanding balance of convertible note including accrued unpaid interest             $ 4,200,000          
Convertible note, redeemed amount             $ 655,000          
Subsequent Event | DavidF Welch [Member]                        
Subsequent Event [Line Items]                        
Warrants to purchase common shares, shares                     1,000,000  
Subsequent Event | DavidF Welch [Member] | Additional Shares [Member]                        
Subsequent Event [Line Items]                        
Warrants to purchase common shares, shares                     500,000