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Commitments and Contingencies - Additional Information (Detail) - USD ($)
 3 Months Ended 12 Months Ended
May 31, 2023
May 31, 2023
May 31, 2022
May 31, 2021
Commitments and Contingencies Disclosure [Line Items]        
Estimated liability costs of remediation $ 916,000 $ 916,000 $ 916,000  
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Liabilities Liabilities Liabilities  
Estimated liability, measurement period, years   15 years    
Estimated liability costs of remediation, current $ 100,000 $ 100,000    
Testing and treatment costs   $ 85,000    
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] Liabilities, Current Liabilities, Current    
Royalty Expense   $ 3,392,000 $ 1,999,000 $ 2,129,000
Future minimum royalty payment for period, 2024 $ 112,000 112,000    
Future minimum royalty payment for period, 2025 109,000 109,000    
Future minimum royalty payment for period, 2026 84,000 84,000    
Future minimum royalty payment for period, 2027 84,000 84,000    
Future minimum royalty payment for period, 2028 67,000 67,000    
Estimated liability costs of remediation, non current $ 816,000 $ 816,000    
Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other Liabilities, Noncurrent Other Liabilities, Noncurrent    
Accrual reversed $ 600,000      
Environmental loss contingencies, charges to expense for potential fines or penalties   $ 600,000    
Debt issuance costs incurred $ 6,683,000 6,683,000    
Minimum        
Commitments and Contingencies Disclosure [Line Items]        
Environmental remediation expense   $ 63,000    
Environmental Remediation Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]   Operating Expenses    
Maximum        
Commitments and Contingencies Disclosure [Line Items]        
Environmental remediation expense   $ 131,000    
Environmental Remediation Expense, Statement of Income or Comprehensive Income [Extensible Enumeration]   Operating Expenses