Quarterly report pursuant to Section 13 or 15(d)

Stock Options and Warrants - Additional Information (Detail)

v3.3.1.900
Stock Options and Warrants - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended
Nov. 30, 2015
Nov. 30, 2014
Nov. 30, 2015
Nov. 30, 2014
Feb. 28, 2015
Private Equity Offering          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 11,724,092   11,724,092    
Warrant covering common stock shares purchased, percentage     50.00%    
Common stock, par value      
Exercise price of warrants, per share $ 0.75   $ 0.75    
Term of warrants     5 years    
Private Equity Offering | Investor Warrants          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 10,344,092   10,344,092    
Private Equity Offering | Alpha Venture Capital Partners, L.P.          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 1,000,000   1,000,000    
Private Equity Offering | Placement Agent          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 1,716,643   1,716,643    
Exercise price of warrants, per share $ 0.75   $ 0.75    
Term of warrants     5 years    
Consultant | Private Equity Offering          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 380,000   380,000    
Black Scholes Valuation Model | Private Equity Offering | Placement Agent          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vested restricted stock awards     776,000    
2012 Equity Incentive Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options grant date fair value     $ 0.42    
Compensation expense related to stock options and warrants $ 238,700 $ 150,000 $ 590,700 $ 287,800  
Grant date fair value of options 123,000 $ 227,000 324,000 $ 309,000  
Unrecognized compensation costs $ 1,391,000   $ 1,391,000    
Weighted average period over which unrecognized compensation costs is expected to be recognized     1 year 5 months 9 days    
2012 Equity Incentive Plan | Third Party Consulting Firm and Scientific Advisor          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 200,000   200,000    
Exercise price of warrants, per share $ 1.02   $ 1.02    
Warrants, termination date     Jul. 13, 2025    
2012 Equity Incentive Plan | Yearly Vesting | Third Party Consulting Firm and Scientific Advisor          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Exercisable warrants, vesting percentage     50.00%    
2012 Equity Incentive Plan | Tranche 1 | Third Party Consulting Firm and Scientific Advisor          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants, exercisable date     Jan. 01, 2016    
2012 Equity Incentive Plan | Tranche 2 | Third Party Consulting Firm and Scientific Advisor          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants, exercisable date     Jan. 01, 2017    
2012 Equity Incentive Plan | Consultant One          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 170,000   170,000    
Exercise price of warrants, per share $ 1.02   $ 1.02    
Exercisable warrants, expire period     5 years    
2012 Equity Incentive Plan | Third party consultant Two          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants granted to purchase common stock shares 10,000   10,000    
Exercise price of warrants, per share $ 1.02   $ 1.02    
Exercisable warrants, expire period     5 years    
2012 Equity Incentive Plan | Stock Options          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares available for future stock-based grants 404,930   404,930    
2012 Equity Incentive Plan | Stock Options | Directors          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options granted, shares     350,000    
Stock options granted, exercise price     $ 0.975    
Stock options, vesting period     1 year    
Stock options grant date fair value     $ 0.49    
2012 Equity Incentive Plan | Stock Options | Directors | Quarterly Vesting          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Exercisable warrants, vesting percentage     25.00%    
2012 Equity Incentive Plan | Stock Options | Director 1          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options granted, exercise price     $ 0.97    
Stock options grant date fair value     $ 0.43    
Stock options, number of shares vested     250,000    
2012 Equity Incentive Plan | Stock Options | Executive Management          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options granted, shares     1,750,000    
2012 Equity Incentive Plan | Stock Options | Executive Management and Employee          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options, vesting period     3 years    
Stock options grant date fair value     $ 0.58    
Exercisable warrants, expire period     10 years    
Stock options granted, exercise price     $ 0.87    
Stock options granted, exercise price     $ 0.90    
Stock options granted, number of shares covered by one option 100,000   100,000    
2012 Equity Incentive Plan | Stock Options | Executive Management and Employee | Stock Option Grant Date          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Exercisable warrants, vesting percentage     50.00%    
2012 Equity Incentive Plan | Stock Options | Executive Management and Employee | Vesting Schedule One          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options, number of shares vested     1,350,000    
2012 Equity Incentive Plan | Stock Options | Executive Management and Employee | Vesting Schedule Two          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock options, number of shares vested     400,000    
2012 Equity Incentive Plan | Stock Options | Before Amendment          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares available for future issuance         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         5,000,000