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Commitments and Contingencies - Additional Information (Detail) - USD ($)
 3 Months Ended
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