Quarterly report pursuant to Section 13 or 15(d)

Note 17 - Stockholders' Equity (Details) - Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range

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Note 17 - Stockholders' Equity (Details) - Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range - $ / shares
 3 Months Ended 12 Months Ended
May 31, 2018
Aug. 31, 2019
May 31, 2019
Jul. 19, 2019
Jul. 08, 2019
Aug. 14, 2018
May 30, 2018
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]              
Exercise Price       $ 1.10 $ 1.10 $ 0.75  
Number of warrants outstanding (in Shares)   54,835,145 54,818,985       4,497,750
Weighted average remaining contractual life   2 years 6 months          
Weighted average exercise price of outstanding warrants $ 0.61 $ 0.53 $ 0.53        
Number of warrants exercisable (in Shares)   54,835,145          
Weighted average exercise price of exercisable warrants   $ 0.53          
Warrant Exercisable at $0.49 [Member]              
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]              
Exercise Price   $ 0.49          
Number of warrants outstanding (in Shares)   33,465,110          
Weighted average remaining contractual life   2 years 3 months          
Weighted average exercise price of outstanding warrants   $ 0.49          
Number of warrants exercisable (in Shares)   33,465,110          
Weighted average exercise price of exercisable warrants   $ 0.49          
Warrants Exercisable at $0.50 [Member]              
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]              
Exercise Price   $ 0.50          
Number of warrants outstanding (in Shares)   2,736,500          
Weighted average remaining contractual life   2 years 175 days          
Weighted average exercise price of outstanding warrants   $ 0.50          
Number of warrants exercisable (in Shares)   2,736,500          
Weighted average exercise price of exercisable warrants   $ 0.50          
Warrant Exercisable at $0.60 [Member]              
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]              
Exercise Price   $ 0.60          
Number of warrants outstanding (in Shares)   17,500,000          
Weighted average remaining contractual life   2 years 3 months          
Weighted average exercise price of outstanding warrants   $ 0.60          
Number of warrants exercisable (in Shares)   17,500,000          
Weighted average exercise price of exercisable warrants   $ 0.60          
Warrant Exercisable at $0.75 [Member]              
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]              
Exercise Price   $ 0.75          
Number of warrants outstanding (in Shares)   837,500          
Weighted average remaining contractual life   1 year 171 days          
Weighted average exercise price of outstanding warrants   $ 0.75          
Number of warrants exercisable (in Shares)   837,500          
Weighted average exercise price of exercisable warrants   $ 0.75          
Warrant Exercisable at $1.10 [Member]              
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]              
Exercise Price   $ 1.10          
Number of warrants outstanding (in Shares)   296,035          
Weighted average remaining contractual life   2 years 116 days          
Weighted average exercise price of outstanding warrants   $ 1.10          
Number of warrants exercisable (in Shares)   296,035          
Weighted average exercise price of exercisable warrants   $ 1.10