Annual report [Section 13 and 15(d), not S-K Item 405]

Income Taxes (Reconciliation of U.S. Federal Statutory Tax Rate) (Details)

v3.25.2
Income Taxes (Reconciliation of U.S. Federal Statutory Tax Rate) (Details)
12 Months Ended
May 31, 2025
May 31, 2024
May 31, 2023
Income Tax Disclosure [Abstract]      
Federal statutory tax rate 21.00% 21.00% 21.00%
Increase/(decrease) resulting from:      
State income taxes, net of federal tax benefit 4.20% 4.00% 4.20%
Stock option windfall benefit (0.40%) (0.40%) (0.40%)
Tax credits (1.10%) (0.80%) (0.70%)
Other items 0.10%   (0.10%)
Effective income tax rate 23.80% 23.80% 24.00%