Annual report pursuant to Section 13 and 15(d)

Equity Awards and Warrants - Options, RSUs, PSUs (Details)

v3.21.2
Equity Awards and Warrants - Options, RSUs, PSUs (Details)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Oct. 16, 2020
shares
Sep. 30, 2020
shares
Jun. 25, 2020
item
$ / shares
shares
Jan. 28, 2020
shares
Sep. 30, 2020
$ / shares
shares
May 31, 2021
USD ($)
item
$ / shares
shares
May 31, 2020
USD ($)
shares
Aug. 31, 2020
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of active plans | item           1    
Number of inactive plans | item           1    
Options outstanding, vested           12,800,000 12,900,000  
Options outstanding, nonvested           5,800,000 2,700,000  
Stock option exercises, shares           2,600,000    
Proceeds from stock option exercises | $           $ 1,839 $ 5,602  
Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock options exercised, exercise price | $ / shares           $ 1.40    
Minimum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock options exercised, exercise price | $ / shares           $ 0.30    
Executives                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock option granted, Shares         3,350,000      
Stock option granted, exercise price | $ / shares         $ 3.12      
Stock options grant date fair value | $ / shares         $ 2.12      
Director [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock option granted, Shares     675,000          
Stock option granted, exercise price | $ / shares     $ 6.15          
Stock options grant date fair value | $ / shares     $ 4.20          
Management, Employees And Consultants [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock option granted, Shares           2,300,000    
Management, Employees And Consultants [Member] | Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock option granted, exercise price | $ / shares           $ 6.15    
Stock options grant date fair value | $ / shares           4.46    
Management, Employees And Consultants [Member] | Minimum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock option granted, exercise price | $ / shares           2.02    
Stock options grant date fair value | $ / shares           $ 1.53    
Stock Options | Executives                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock option granted, Shares   3,350,000            
Award vesting period   3 years     3 years      
Stock Options | Director [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of nonemployee directors | item     3          
Options subject to shareholder approval     506,250          
Award vesting period     1 year          
Stock Options | Management, Employees And Consultants [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Award vesting period           3 years    
Options term           10 years    
Restricted Stock Units (RSUs) [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock units granted, shares 200,000              
Award vesting period 3 years              
Restricted Stock Units (RSUs) [Member] | Executives                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock units granted, shares   1,120,000     1,120,000      
Award vesting period   3 years     3 years      
Units granted, grant date fair value | $ / shares         $ 3.12      
Performance Shares [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock units granted, shares       11,700,000        
Award vesting period       6 months        
Performance Shares [Member] | Executives                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock units granted, shares   4,350,000     4,350,000      
2012 Equity Incentive Plan                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of shares authorized for issuance           50,000,000   25,000,000
Annual increase in shares authorized, as a percent of outstanding shares           1.00%    
Plan extension period           10 years    
Shares available for future stock-based grants           15,300,000