Quarterly report pursuant to Section 13 or 15(d)

Consolidated Balance Sheets (Parenthetical)

v3.20.4
Consolidated Balance Sheets (Parenthetical) - $ / shares
Nov. 30, 2020
May 31, 2020
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 5,000,000 5,000,000
Common stock, par value $ 0.001 $ 0.001
Common stock, shares authorized 800,000,000 800,000,000
Common stock, shares issued 590,279,000 519,261,000
Common stock, shares outstanding 589,837,000 518,976,000
Treasury stock, shares 442,000 286,000
Treasury Stock    
Common stock, par value $ 0.001 $ 0.001
Series D Convertible Preferred Stock    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 12,000 12,000
Preferred stock, shares issued 9,000 9,000
Preferred stock, shares outstanding 9,000 9,000
Series B Convertible Preferred Stock    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 400,000 400,000
Preferred stock, shares issued 87,000 92,000
Preferred stock, shares outstanding 87,000 92,000
Series C Convertible Preferred Stock    
Preferred stock, par value $ 0.001 $ 0.001
Preferred stock, shares authorized 8,000 8,000
Preferred stock, shares issued 8,000 8,000
Preferred stock, shares outstanding 8,000 8,000