The Debt Service Ratio (DSR) requirement per the terms of long-term debt agreements.

No definition available.

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- Definition

The Equity to Capitalization Ratio (ECR) requirement per the terms of long-term debt agreements.

+ References

No definition available.

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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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Face (par) amount of debt instrument at time of issuance.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt classified as noncurrent. Excludes lease obligation.

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The cash inflow from amounts received from issuance of long-term debt that is wholly or partially secured by collateral. Excludes proceeds from tax exempt secured debt.

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LONG-TERM DEBT - Narrative (Details) - USD ($)				12 Months Ended
LONG-TERM DEBT - Narrative (Details) - USD ($)	Dec. 19, 2023	Jun. 13, 2023	Mar. 24, 2023	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt				$ 2,896,506,000	$ 2,869,963,000
Outstanding borrowings				3,137,534,000	2,981,481,000
2022 Revolving Credit Agreement \| Commercial Paper
Debt Instrument [Line Items]
Available borrowing capacity				315,000,000
2022 Revolving Credit Agreement \| Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity				520,000,000
Outstanding borrowings				0
Available borrowing capacity				336,000,000
Series B, 7.14%, due through 2033
Debt Instrument [Line Items]
Outstanding borrowings				200,503,000	248,601,000
CoBank Variable Rate Syndicated Multiple Advance Term Loan \| Secured Debt
Debt Instrument [Line Items]
Outstanding borrowings			$ 100,000,000
Term of debt instrument			2 years
Face amount of debt instrument			$ 150,000,000
Proceeds from issuance of secured debt		$ 50,000,000
2.32% to 6.44% CFC, due through 2050
Debt Instrument [Line Items]
Outstanding borrowings				177,260,000	85,855,000
2.32% to 6.44% CFC, due through 2050 \| Secured Debt
Debt Instrument [Line Items]
Term of debt instrument	27 years
Face amount of debt instrument	$ 100,000,000
First Mortgage Bonds, Series 2014E-1, 3.70% due 2024
Debt Instrument [Line Items]
Outstanding borrowings				128,002,000	$ 128,002,000
First Mortgage Bonds, Series 2014E-1, 3.70% due 2024 \| Secured Debt
Debt Instrument [Line Items]
Outstanding borrowings				$ 128,000,000
Minimum
Debt Instrument [Line Items]
Equity to capitalization ratio (ECR) requirement (as a percent)				18.00%
Debt service ratio (DSR) requirement				1.025
Minimum \| All Other Long-Term Debt
Debt Instrument [Line Items]
Debt service ratio (DSR) requirement				1.10
Minimum \| Series B, 7.14%, due through 2033 \| Mortgages
Debt Instrument [Line Items]
Debt service ratio (DSR) requirement				1.02