v3.26.1
Postretirement Benefits - Additional Information (Detail)
$ in Millions
May 31, 2026
USD ($)
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]  
Estimated benefits payable in the first year $ 78.8
Estimated benefits payable in the second year 81.7
Estimated benefits payable in the third year 92.0
Estimated benefits payable in the fourth year 91.4
Estimated benefits payable in the fifth year 94.9
Estimated benefits payable in the years thereafter 485.4
Postretirement Benefits  
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]  
Estimated benefits payable in the years thereafter 8.1
Minimum | Postretirement Benefits  
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]  
Estimated benefits payable in the first year 1.2
Estimated benefits payable in the second year 1.2
Estimated benefits payable in the third year 1.2
Estimated benefits payable in the fourth year 1.2
Estimated benefits payable in the fifth year 1.2
Maximum | Postretirement Benefits  
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]  
Estimated benefits payable in the first year 1.4
Estimated benefits payable in the second year 1.4
Estimated benefits payable in the third year 1.4
Estimated benefits payable in the fourth year 1.4
Estimated benefits payable in the fifth year $ 1.4