Quarterly report pursuant to Section 13 or 15(d)

Convertible Instruments and Accrued Interest - Preferred stock (Details)

v3.23.1
Convertible Instruments and Accrued Interest - Preferred stock (Details)
$ / shares in Units, shares in Thousands, $ in Thousands
 9 Months Ended 12 Months Ended
Feb. 28, 2023
USD ($)
$ / shares
shares
May 31, 2022
USD ($)
shares
Class of Stock [Line Items]    
Accrued dividends | $ $ 4,935 $ 3,977
Series B Convertible Preferred Stock    
Class of Stock [Line Items]    
Shares of preferred stock 19 19
Common stock conversion rate 10 10
Total shares of common stock if converted 190 190
Undeclared dividend | $ $ 14 $ 10
Total shares of common stock if dividends converted 28 20
Preferred Stock, Liquidation Preference Per Share | $ / shares $ 5.00  
Series C Convertible Preferred Stock    
Class of Stock [Line Items]    
Shares of preferred stock 6 7
Common stock conversion rate 2,000 2,000
Total shares of common stock if converted 12,670 13,806
Accrued dividends | $ $ 2,341 $ 2,014
Total shares of common stock if dividends converted 4,682 4,028
Series D Convertible Preferred Stock    
Class of Stock [Line Items]    
Shares of preferred stock 9 9
Common stock conversion rate 1,250 1,250
Total shares of common stock if converted 10,565 10,565
Accrued dividends | $ $ 2,594 $ 1,963
Total shares of common stock if dividends converted 5,188 3,926
Series C and Series D Convertible Preferred Stock    
Class of Stock [Line Items]    
Preferred Stock, Liquidation Preference Per Share | $ / shares $ 1,000