Annual report pursuant to Section 13 and 15(d)

Consolidated Statement of Changes in Stockholders' (Deficit) Equity (Parenthetical)

v3.19.2
Consolidated Statement of Changes in Stockholders' (Deficit) Equity (Parenthetical) - $ / shares
 12 Months Ended
May 31, 2019
May 31, 2018
May 31, 2017
Proceeds from private equity offering, per share $ 0.50 $ 0.50 $ 1.00
Proceeds from registered direct offering, per share 0.50 0.50 0.75
Exercise Price 1 [Member]      
Warrants Granted Per Share     0.50
Exercise Price 2 [Member]      
Warrants Granted Per Share     0.75
Common Stock [Member]      
Warrants Granted Per Share   0.50  
Proceeds from private equity offering, per share 0.50 0.50 1.00
Proceeds from registered direct offering, per share 0.50 0.50 0.75
Additional Paid-in Capital [Member]      
Proceeds from private equity offering, per share 0.50 0.50 1.00
Proceeds from registered direct offering, per share $ 0.50 $ 0.50 0.75
Series B Preferred Stock [Member]      
Proceeds from private equity offering, per share     $ 0.50