Variable Interest Entities - Information on CFCs Credit Commitments to NCSC and RTFC (Details) - USD ($) $ in Thousands	Feb. 28, 2023	May 31, 2022
Variable Interest Entity [Line Items]
CFC third-party guarantees	$ 775,807	$ 730,783
Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Total CFC credit commitments	5,500,000	5,500,000
Borrowings payable to CFC	1,456,045	1,158,583
CFC third-party guarantees	27,964	23,970
Other credit enhancements	1,541	4,044
Total credit enhancements	29,505	28,014
Total outstanding commitments	1,485,550	1,186,597
CFC credit commitments available	$ 4,014,450	$ 4,313,403