Quarterly report [Sections 13 or 15(d)]

Convertible Instruments and Accrued Interest - Preferred stock (Details)

v3.25.1
Convertible Instruments and Accrued Interest - Preferred stock (Details)
$ / shares in Units, shares in Thousands, $ in Thousands
 9 Months Ended 12 Months Ended
Feb. 28, 2025
USD ($)
$ / shares
shares
May 31, 2024
USD ($)
$ / shares
shares
Nov. 30, 2024
$ / shares
Class of Stock      
Accrued dividends | $ $ 7,897 $ 6,791  
Preferred stock, par value | $ / shares   $ 0.001 $ 0.001
Accumulated deficit | $ $ (881,830) $ (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 | $ $ 23 $ 19  
Total shares of common stock if dividends converted 46 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 | $ $ 3,610 $ 3,135  
Total shares of common stock if dividends converted 7,220 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 | $ $ 4,287 $ 3,656  
Total shares of common stock if dividends converted 8,574 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