Quarterly report pursuant to Section 13 or 15(d)

Private Equity Securities Offerings (Detail)

v3.21.4
Private Equity Securities Offerings (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 6 Months Ended
Nov. 30, 2021
Aug. 31, 2021
Nov. 30, 2020
Aug. 31, 2020
Nov. 30, 2021
Nov. 30, 2020
Class of Stock [Line Items]            
Proceeds from warrant transactions, net of offering costs         $ 5,390 $ 12,035
Private Equity Offering            
Class of Stock [Line Items]            
Stock price, in dollars per share   $ 1.00 $ 1.50     $ 1.50
Stock issued via offering, tender or placement, value $ 27,307 $ 2,872 $ 1,000      
Private Equity Offering | Maximum            
Class of Stock [Line Items]            
Stock price, in dollars per share $ 1.80       $ 1.80  
Private Equity Offering | Minimum            
Class of Stock [Line Items]            
Stock price, in dollars per share $ 1.00       $ 1.00  
Accredited Investors [Member]            
Class of Stock [Line Items]            
Shares issued during the period new issues shares         16,700,000  
Number Of Common Shares In Fixed Combination Issue Of shares 1       1  
Number Of Warrants In Fixed Combination Issue Of Securities 0.25       0.25  
Common stock warrants to purchase shares 4,200,000       4,200,000  
Term of warrants 5 years       5 years  
Stock issued via offering, tender or placement, value         $ 18,800  
Accredited Investors [Member] | Maximum            
Class of Stock [Line Items]            
Exercise price of warrants, per share $ 1.80       $ 1.80  
Stock price, in dollars per share 1.80       1.80  
Accredited Investors [Member] | Minimum            
Class of Stock [Line Items]            
Exercise price of warrants, per share 1.00       1.00  
Stock price, in dollars per share $ 1.00       $ 1.00  
Private Warrant Exchange [Member]            
Class of Stock [Line Items]            
Shares issued during the period new issues shares         7,900,000  
Proceeds from warrant transactions, net of offering costs         $ 6,400  
Noncash inducement interest expense $ 4,700       $ 5,200  
Stock issued via offering, tender or placement, value $ 4,615 $ 775 $ 4,596 $ 7,804    
Private Warrant Exchange [Member] | Maximum            
Class of Stock [Line Items]            
Exercise price of warrants, per share $ 1.00       $ 1.00  
Private Warrant Exchange [Member] | Minimum            
Class of Stock [Line Items]            
Exercise price of warrants, per share 0.40       $ 0.40  
Private Warrant Exchange, Non-Inducement Shares [Member]            
Class of Stock [Line Items]            
Shares issued during the period new issues shares         3,500,000  
Stock Subscription Agreements [Member]            
Class of Stock [Line Items]            
Exercise price of warrants, per share 1.00       $ 1.00  
Shares issued during the period new issues shares         11,400,000  
Stock price, in dollars per share $ 1.00       $ 1.00  
Number Of Common Shares In Fixed Combination Issue Of shares 1       1  
Number Of Warrants In Fixed Combination Issue Of Securities 0.3       0.3  
Common stock warrants to purchase shares 5,000,000.0       5,000,000.0  
Term of warrants 5 years       5 years  
Proceeds from issuance of common stock         $ 11,400  
Stock issued via offering, tender or placement, value           $ 10,000
Allotment to placement agent            
Class of Stock [Line Items]            
Exercise price of warrants, per share $ 1.00       $ 1.00  
Term of warrants 10 years       10 years  
Warrant covering common stock shares purchased, percentage         12.00%  
Placement agent fees and expenses         $ 50