General form of registration statement for all companies including face-amount certificate companies

Stock Options and Warrants (Detail)

v2.4.0.8
Stock Options and Warrants (Detail) (USD $)
 6 Months Ended 12 Months Ended
Nov. 30, 2013
May 31, 2013
May 31, 2012
May 31, 2011
Stock option and warrant activity        
Options and warrants outstanding, Number of Shares 18,146,938 10,327,664 7,473,576  
Granted, Number of Shares 17,848,540 11,166,274 3,456,088  
Exercised, Number of Shares (50,000) (780,000) (527,500)  
Forfeited /expired/ cancelled, Number of Shares (1,578,645) (2,567,000) (74,500)  
Options and warrants outstanding, Number of Shares 34,366,833 18,146,938 10,327,664 7,473,576
Outstanding exercisable - Number of Shares 32,570,497 16,253,188    
Options and warrants outstanding, Weighted Average Exercise Price $ 1.65 $ 1.60 $ 1.34  
Granted,Weighted Average Exercise Price $ 0.74 $ 1.61 $ 2.04  
Exercised,Weighted Average Exercise Price $ 1.00 $ 0.26 $ 0.62  
Forfeited/expired/cancelled,Weighted Average Exercise Price $ 1.40 $ 1.73 $ 2.49  
Options and warrants outstanding ,Weighted Average Exercise Price $ 1.19 $ 1.65 $ 1.60 $ 1.34
Outstanding exercisable ,Weighted Average Exercise Price $ 1.19 $ 1.68    
Options and warrants outstanding, Weighted Average Remaining Contractual Life 3 years 5 months 19 days 1 year 10 months 10 days 3 years 2 months 12 days 3 years 10 months 2 days
Outstanding exercisable, Weighted Average Remaining Contractual Life 3 years 5 months 16 days 1 year 7 months 24 days    
Options and warrants outstanding , Aggregate Intrinsic Value $ 140,321 $ 2,308,279 $ 10,495,913  
Options and warrants outstanding , Aggregate Intrinsic Value 10,474,005 140,321 2,308,279 10,495,913
Exercisable , Aggregate Intrinsic Value $ 9,902,708 $ 140,321