Variable Interest Entities - Schedule of variable interest entities (Details) - USD ($) $ in Thousands	May 31, 2024	May 31, 2023
Assets:
Other assets	$ 81,822	$ 64,723
Total assets	36,177,814	34,012,060
Liabilities:
Total liabilities	33,165,645	31,422,811
Variable interest entity, primary beneficiary
Assets:
Loans to members	1,544,477	1,444,662
Other assets	12,700	12,612
Total assets	1,557,177	1,457,274
Liabilities:
Total liabilities	$ 9,824	$ 19,704