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 9 Months Ended
Feb. 29, 2016
Feb. 28, 2015
Feb. 29, 2016
Feb. 28, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Warrants to purchase common shares, shares 133,734   133,734  
Exercise price of warrants, per share $ 0.75   $ 0.75  
Proceeds from exercise of warrants, net of offering costs     $ 94,283 $ 1,066,436
Private Equity Offering        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Warrants to purchase common shares, shares 29,827,110   29,827,110  
Exercise price of warrants, per share $ 0.75   $ 0.75  
Term of warrants     5 years  
Private Equity Offering | Alpha Venture Capital Partners, L.P.        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Warrants to purchase common shares, shares 1,000,000   1,000,000  
Private Equity Offering | Consultant        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Warrants to purchase common shares, shares 1,820,000   1,820,000  
Private Equity Offering | Investors        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Warrants to purchase common shares, shares 22,209,178   22,209,178  
Private Equity Offering | Placement Agent        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Warrants to purchase common shares, shares 4,797,932   4,797,932  
2012 Equity Incentive Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Compensation expense $ 955,000 $ 161,400 $ 1,546,000 451,000
Grant date fair value of options and warrants 362,000 $ 171,000 686,000 $ 481,000
Unrecognized compensation costs $ 998,000   $ 998,000  
Weighted average period over which unrecognized compensation costs is expected to be recognized     1 year 2 months 12 days  
2012 Equity Incentive Plan | Consultant | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Exercise price of warrants, per share $ 0.81   $ 0.81  
Warrants, grant date fair value     $ 0.42  
Warrants expiration period     5 years  
2012 Equity Incentive Plan | Consultant | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Exercise price of warrants, per share $ 1.25   $ 1.25  
Warrants, grant date fair value     $ 0.60  
Warrants expiration period     10 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 930   930  
Share-based compensation arrangement by share-based payment award, expiration period     5 years  
Share-based compensation arrangement by share-based payment award, extended expiration period     5 years  
Share price $ 0.81   $ 0.81  
Compensation expense     $ 548,000  
Share-based compensation arrangement by share-based payment award, options outstanding 1,924,513   1,924,513  
Share-based compensation arrangement by share-based payment award, options, weighted average exercise price $ 1.39   $ 1.39  
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  
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]        
Vesting rights 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, shares     250,000  
Stock options granted, exercise price     $ 0.97  
Stock options grant date fair value     $ 0.43  
Share-based compensation arrangement by share-based payment award, expiration period     5 years  
2012 Equity Incentive Plan | Stock Options | Director 2        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options granted, shares     100,000  
Stock options granted, exercise price     $ 0.84  
Stock options grant date fair value     $ 0.58  
Share-based compensation arrangement by share-based payment award, expiration period     5 years  
2012 Equity Incentive Plan | Stock Options | Director 2 | Stock Option Grant Date        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting rights percentage     50.00%  
2012 Equity Incentive Plan | Stock Options | Director 2 | First Anniversary of Grant Date        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting rights percentage     50.00%  
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options granted, shares     2,054,000  
Vesting period     3 years  
Share-based compensation arrangement by share-based payment award, expiration period     10 years  
Stock options granted, exercise price, lower range limit     $ 0.75  
Stock options granted, exercise price, upper range limit     $ 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 Employees | Minimum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options grant date fair value     $ 0.48  
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees | Maximum        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options grant date fair value     $ 0.61  
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees | Stock Option Grant Date        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting rights percentage     50.00%  
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees | First Anniversary of Grant Date        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting rights percentage     50.00%  
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees | Vesting Schedule One        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock options, number of shares vested     1,554,000  
2012 Equity Incentive Plan | Stock Options | Executive Management and Employees | 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   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   5,000,000