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Commitments and Contingencies - Additional Information (Detail) - USD ($)
 3 Months Ended
Nov. 30, 2021
Aug. 31, 2021
May 31, 2021
Commitments and Contingencies Disclosure [Line Items]      
Estimated liability costs of remediation $ 916,000   $ 916,000
Estimated liability, measurement period, years   15 years  
Estimated liability costs of remediation, current 300,000    
Estimated liability costs of remediation, non current 616,000    
Environmental loss contingencies, charges to expense for potential fines or penalties 600,000    
Minimum      
Commitments and Contingencies Disclosure [Line Items]      
Environmental remediation expense 38,000    
Maximum      
Commitments and Contingencies Disclosure [Line Items]      
Environmental remediation expense $ 131,000