Quarterly report pursuant to Section 13 or 15(d)

Convertible Instruments and Accrued Interest - Preferred stock (Details)

v3.24.4
Convertible Instruments and Accrued Interest - Preferred stock (Details)
$ / shares in Units, shares in Thousands, $ in Thousands
 6 Months Ended 12 Months Ended
Nov. 30, 2024
USD ($)
$ / shares
shares
May 31, 2024
USD ($)
$ / shares
shares
Class of Stock    
Accrued dividends | $ $ 7,532 $ 6,791
Preferred stock, par value | $ / shares $ 0.001 $ 0.001
Accumulated deficit | $ $ (877,072) $ (891,531)
Series B Preferred Stock [Member]    
Class of Stock    
Shares of preferred stock outstanding 19 19
Common stock conversion rate 10 10
Total shares of common stock if converted 190 190
Undeclared dividends | $ $ 22 $ 19
Total shares of common stock if dividends converted 44 38
Preferred stock, liquidation preference per share ($ per share) | $ / shares $ 5  
Preferred stock, par value | $ / shares $ 0.001 $ 0.001
Series C Preferred Stock [Member]    
Class of Stock    
Shares of preferred stock outstanding 6 6
Common stock conversion rate 2,000 2,000
Total shares of common stock if converted 12,670 12,670
Accrued dividends | $ $ 3,453 $ 3,135
Total shares of common stock if dividends converted 6,906 6,270
Preferred stock, par value | $ / shares $ 0.001 $ 0.001
Series D Preferred Stock [Member]    
Class of Stock    
Shares of preferred stock outstanding 9 9
Common stock conversion rate 1,250 1,250
Total shares of common stock if converted 10,565 10,565
Accrued dividends | $ $ 4,079 $ 3,656
Total shares of common stock if dividends converted 8,158 7,312
Preferred stock, par value | $ / shares $ 0.001 $ 0.001
Series C and Series D Convertible Preferred Stock    
Class of Stock    
Preferred stock, liquidation preference per share ($ per share) | $ / shares $ 1,000