Quarterly report pursuant to Section 13 or 15(d)

Stock Options and Warrants - Additional Information (Detail)

v3.19.3.a.u2
Stock Options and Warrants - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Oct. 07, 2019
Sep. 12, 2019
Nov. 30, 2019
Nov. 30, 2018
Nov. 30, 2019
Nov. 30, 2018
Sep. 30, 2019
May 22, 2019
Aug. 24, 2017
Mar. 31, 2016
Feb. 28, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock options, term 10 years 10 years                  
Warrants to purchase common shares, shares             200,000        
Exercise price of warrants, per share             $ 0.45        
Compensation expense         $ 1,014,972 $ 1,510,486          
2019 Short-term convertible notes                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Warrants to purchase common shares, shares     4,750,000   4,750,000            
Term of warrants     5 years   5 years            
Minimum | 2019 Short-term convertible notes                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercise price of warrants, per share     $ 0.30   $ 0.30            
Maximum | 2019 Short-term convertible notes                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercise price of warrants, per share     $ 0.45   $ 0.45            
Placement Agent                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Warrants to purchase common shares, shares     655,305   655,305            
Term of warrants     5 years   5 years            
Placement Agent | Minimum                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercise price of warrants, per share     $ 0.40   $ 0.40            
Placement Agent | Maximum                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercise price of warrants, per share     $ 0.444   $ 0.444            
Investor | Series C Convertible Preferred Stock [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Warrants to purchase common shares, shares     9,601,000   9,601,000            
Term of warrants     5 years   5 years            
Investor | Minimum | Series C Convertible Preferred Stock [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercise price of warrants, per share     $ 0.30   $ 0.30            
Investor | Maximum | Series C Convertible Preferred Stock [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Exercise price of warrants, per share     $ 0.50   $ 0.50            
Subscription Agreements                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Warrants to purchase common shares, shares     11,987,250   11,987,250            
Exercise price of warrants, per share     $ 0.45   $ 0.45            
2012 Equity Incentive Plan                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Compensation expense     $ 1,000,000 $ 1,500,000 $ 434,000 1,200,000          
Grant date fair value of options and warrants         907,000 $ 1.2          
Unrecognized compensation expense     $ 1,100,000   $ 1,100,000            
Weighted average period over which unrecognized compensation expense is expected to be recognized         8 months 19 days            
2012 Equity Incentive Plan | Executive Management and Employees                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, Shares         1,112,500            
Stock options, term         10 years            
2012 Equity Incentive Plan | Consultant                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, Shares         400,000            
2012 Equity Incentive Plan | Consultant | Tranche One                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option vested, Shares         200,000            
2012 Equity Incentive Plan | Consultant | Tranche Two                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option vested, Shares         100,000            
2012 Equity Incentive Plan | Consultant | Tranche Three                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option vested, Shares         100,000            
2012 Equity Incentive Plan | Employee Stock Option One | Range Two                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, exerices price         $ 0.90            
2012 Equity Incentive Plan | Employee Stock Option One | Director                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option vested, Shares     1,000,000                
2012 Equity Incentive Plan | Employee Stock Option One | Director | Range One                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, Shares         1,975,000            
Vesting period         1 year            
Stock options, term         10 years            
2012 Equity Incentive Plan | Employee Stock Option One | Director | Minimum                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, exerices price         $ 0.385            
2012 Equity Incentive Plan | Employee Stock Option One | Director | Maximum                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, exerices price         $ 0.52            
2012 Equity Incentive Plan | Employee Stock Option One | Managing Director | Range One                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock options grant date fair value         $ 413,774            
2012 Equity Incentive Plan | Stock Options                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Shares available for future stock-based grants     8,171,644   8,171,644            
2012 Equity Incentive Plan | Stock Options | Before Amendment                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Shares available for future issuance               15,000,000 7,000,000 5,000,000 3,000,000
2012 Equity Incentive Plan | Stock Options | After Amendment                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Shares available for future issuance               25,000,000 15,000,000 7,000,000 5,000,000
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Vesting period         3 years            
Stock options, term         10 years            
Warrants to purchase common shares, shares     50,000   50,000            
2012 Equity Incentive Plan | Stock Options | Executive Management, Employee and Consultant                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, Shares         1,787,500            
Stock options grant date fair value         $ 331,317            
2012 Equity Incentive Plan | Stock Options | Executive Management, Employee and Consultant | Tranche One                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Warrants to purchase common shares, shares     1,112,500   1,112,500            
2012 Equity Incentive Plan | Stock Options | Executive Management, Employee and Consultant | Minimum                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, exerices price         $ 0.30            
2012 Equity Incentive Plan | Stock Options | Executive Management, Employee and Consultant | Maximum                      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Stock option granted, exerices price         $ 0.52