Variable Interest Entities - Schedule of variable interest entities (Details) - USD ($) $ in Thousands	May 31, 2026	May 31, 2025
Assets:
Other assets	$ 91,217	$ 85,528
Total assets	39,704,347	38,325,049
Liabilities:
Total liabilities	36,392,211	35,221,583
Variable interest entity, primary beneficiary
Assets:
Loans outstanding	1,656,398	1,654,228
Other assets	29,290	16,111
Total assets	1,685,688	1,670,339
Liabilities:
Total liabilities	$ 14,909	$ 15,114