Quarterly report pursuant to sections 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v2.4.0.6
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
 3 Months Ended 6 Months Ended 109 Months Ended
Nov. 30, 2012
Nov. 30, 2011
Nov. 30, 2012
Nov. 30, 2011
Nov. 30, 2012
May 31, 2012
Class of Stock [Line Items]            
Net loss $ 1,908,486 $ 1,497,399 $ 4,723,652 $ 2,664,188 $ 27,556,258  
Accumulated deficit 29,158,170   29,158,170   29,158,170  
Working capital deficit 3,055,255   3,055,255   3,055,255  
Cash equivalents 0   0   0  
FDIC coverage per depositor 250,000   250,000   250,000  
Estimated future unvested option forfeitures     0.00%      
Deferred offering costs 559,440   559,440   559,440 677,327
Common stock options and warrants to purchase 17,968,340 7,948,076 17,968,340 7,948,076    
Convertible preferred stock, shares outstanding 96,100   96,100   96,100 98,900
Face amount of notes 5,648,250   5,648,250   5,648,250  
Unrecognized benefits $ 0   $ 0   $ 0  
Investor
            
Class of Stock [Line Items]            
Warrants to purchase common shares, shares 7,530,676   7,530,676   7,530,676  
Series B convertible preferred stock
            
Class of Stock [Line Items]            
Convertible preferred stock, shares outstanding 96,100   96,100   96,100  
Common stock shares issued up on conversion of preferred stock     961,000