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Represents the information pertaining to interest coverage ratio.

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Minimum liquidity to extend maturity to full term.

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No definition available.

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Represents the ratio of debt to cash flow.

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The contingent increase above the maximum borrowing capacity under the credit facility, if any one or more of the existing banks or new banks agree to provide such increased commitment amount.

+ References

No definition available.

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Maximum borrowing capacity under the debt facility.

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No definition available.

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Minimum debt to cash flow ratio for restriction to apply on cash distribution.

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No definition available.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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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).

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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No definition available.

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The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

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Long-Term Debt - Credit Facility (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 13, 2023	Sep. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Debt issuance costs incurred		$ 0	$ 11,442
Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 425,000
Increase of maximum borrowing capacity	100,000
Minimum liquidity to extend maturity	$ 200,000
Letters of credit outstanding		41,000
Debt available for borrowing		$ 384,000
Annual commitment fee percentage, undrawn portion		0.50%
Minimum debt to cash flow ratio for restriction to apply on cash distribution	1
Interest coverage ratio	3
Credit Agreement \| Overnight Bank Funding Rate
Debt Instrument [Line Items]
Basis spread for variable interest rate (as a percent)	0.50%
Credit Agreement \| Daily Simple Secured Overnight Financing Rate
Debt Instrument [Line Items]
Basis spread for variable interest rate (as a percent)	1.00%
Credit Agreement \| Alliance Coal
Debt Instrument [Line Items]
ARLP debt arrangements requirements, debt to cash flow ratio	1.5
Actual debt to cash flow ratio for trailing twelve months		0.15
Credit Agreement \| Alliance Coal and Intermediate Partnership
Debt Instrument [Line Items]
ARLP debt arrangements requirements, debt to cash flow ratio	2.5
Swingline subfacility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 15,000
Term loan
Debt Instrument [Line Items]
Maximum borrowing term loan	$ 75,000
Interest rate (as a percent)	6.25%
Effective interest rate (as a percent)		7.92%