Quarterly report pursuant to Section 13 or 15(d)

Stock Options and Warrants (Detail)

v3.8.0.1
Stock Options and Warrants (Detail) - USD ($)
 9 Months Ended 12 Months Ended
Feb. 28, 2018
May 31, 2017
Stock option and warrant activity    
Options and warrants outstanding, Number of Shares 77,859,626  
Granted, Number of Shares 60,465,027  
Exercised, Number of Shares (3,295,000)  
Forfeited/expired/cancelled, Number of Shares (4,572,322)  
Options and warrants outstanding, Number of Shares 130,457,331 77,859,626
Outstanding exercisable, Number of Shares 126,763,665  
Options and warrants outstanding, Weighted Average Exercise Price $ 0.86  
Granted, Weighted Average Exercise Price 0.75  
Exercised, Weighted Average Exercise Price 0.50  
Forfeited/expired/cancelled, Weighted Average Exercise Price 0.94  
Options and warrants outstanding, Weighted Average Exercise Price 0.80 $ 0.86
Outstanding exercisable, Weighted Average Exercise Price $ 0.80  
Options and warrants outstanding, Weighted Average Remaining Contractual Life 3 years 11 months 8 days 3 years 4 months 24 days
Outstanding exercisable, Weighted Average Remaining Contractual Life 3 years 9 months 22 days  
Options and warrants outstanding, Aggregate Intrinsic Value $ 5,522,382 $ 40,250
Outstanding exercisable, Aggregate Intrinsic Value $ 5,188,052