Annual report pursuant to Section 13 and 15(d)

STOCKHOLDERS??? EQUITY (Details) - Fair Value Measurement Inputs and Valuation Techniques

v3.19.2
STOCKHOLDERS’ EQUITY (Details) - Fair Value Measurement Inputs and Valuation Techniques
May 31, 2019
May 31, 2018
Measurement Input, Price Volatility [Member] | Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement Input 79.02 99.36
Measurement Input, Price Volatility [Member] | Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement Input 4.003 0.9953
Measurement Input, Expected Dividend Rate [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement Input 0 0
Measurement Input, Risk Free Interest Rate [Member] | Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement Input 0.0268 0.0252
Measurement Input, Risk Free Interest Rate [Member] | Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement Input 0.0277 0.0265
Measurement Input, Expected Term [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Measurement Input 3 3