Long-Term Debt - Long-Term Debt Outstanding (Details) - USD ($) $ in Thousands	Nov. 30, 2021	May 31, 2021
Long-term debt
Long-term debt	$ 20,804,379	$ 20,603,123
Collateral trust bonds
Long-term debt
Long-term debt, gross	7,047,711	7,452,711
Unamortized discount	(221,016)	(227,046)
Debt issuance costs	(31,205)	(33,721)
Long-term debt	6,795,490	7,191,944
Guaranteed Underwriter Program notes payable
Long-term debt
Long-term debt	6,290,600	6,269,303
Farmer Mac notes payable
Long-term debt
Long-term debt	3,121,485	2,977,909
Other secured notes payable
Long-term debt
Long-term debt, gross	4,412	4,412
Debt issuance costs	(14)	(22)
Long-term debt	4,398	4,390
Notes payable
Long-term debt
Long-term debt	9,416,483	9,251,602
Secured debt
Long-term debt
Long-term debt	16,211,973	16,443,546
Medium-term notes sold through dealers
Long-term debt
Long-term debt, gross	4,406,592	3,943,728
Medium-term notes sold to members
Long-term debt
Long-term debt, gross	202,710	232,346
Medium term notes sold through dealers and to members
Long-term debt
Long-term debt, gross	4,609,302	4,176,074
Unamortized discount	(2,315)	(2,307)
Debt issuance costs	(18,446)	(18,036)
Long-term debt	4,588,541	4,155,731
Other unsecured notes payable
Long-term debt
Long-term debt, gross	3,886	3,886
Unamortized discount	(19)	(35)
Debt issuance costs	(2)	(5)
Unsecured notes payable
Long-term debt
Long-term debt	3,865	3,846
Unsecured debt
Long-term debt
Long-term debt	$ 4,592,406	$ 4,159,577

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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