Variable Interest Entities - Schedule of Assets and Liabilities of Variable Interest Entities (Details) - USD ($) $ in Thousands	Feb. 28, 2026	May 31, 2025	Feb. 28, 2025
Assets:
Other assets	$ 94,559	$ 85,528
Total assets	39,892,933	38,325,049	$ 37,778,743
Liabilities:
Total liabilities	36,796,204	35,221,583
Variable Interest Entity, Primary Beneficiary
Assets:
Loans outstanding	1,782,379	1,654,228
Other assets	26,064	16,111
Total assets	1,808,443	1,670,339
Liabilities:
Total liabilities	$ 15,683	$ 15,114