Annual report pursuant to Section 13 and 15(d)

Equity Awards and Warrants - Stock Options and Other Equity Awards (Details)

v3.23.2
Equity Awards and Warrants - Stock Options and Other Equity Awards (Details) - $ / shares
shares in Thousands
12 Months Ended
Feb. 13, 2023
May 31, 2023
May 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options outstanding, vested   12,000 9,900
Options outstanding, nonvested   7,800 7,500
Shares issued during the period new issues shares 400    
Common Stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Warrant exercises (in shares)   1,898 1,642
Management, Employees And Consultants [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option granted, Shares   1,800  
Management, Employees And Consultants [Member] | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option granted, exercise price   $ 0.67  
Stock options grant date fair value   0.54  
Management, Employees And Consultants [Member] | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option granted, exercise price   0.35  
Stock options grant date fair value   0.29  
Stock Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock option granted, exercise price   $ 0.41 $ 1.38
Stock options exercised, exercise price     $ 0.79
Stock Options | Management, Employees And Consultants [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options term   10 years  
Award vesting period   4 years  
Restricted Stock Units (RSUs) [Member] | Executives      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Issuance of common stock upon vesting of stock based compensation awards, shares   200