The amount of accrued loss recovery asset.

No definition available.

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- Definition

The number of raw coal storage silos.

+ References

No definition available.

+ Details

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- Definition

The number of raw coal storage silos that experienced partial structure failure.

+ References

No definition available.

+ Details

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- Definition

The percent of plant capacity restored after partial structural failure.

+ References

No definition available.

+ Details

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- Definition

Total costs accrued as of the balance sheet date for environmental loss contingencies.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
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Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
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Balance Type:	credit
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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 410
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- Definition

Amount awarded from other party in judgment or settlement of litigation.

+ References

No definition available.

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- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
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- Definition

Amount of damages awarded to the plaintiff in the legal matter.

+ References

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Data Type:	xbrli:monetaryItemType
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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.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(3))
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- Details

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- Details

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Note 7 - Commitments and Contingencies (Details) $ in Millions						3 Months Ended		9 Months Ended
	Jul. 20, 2023 USD ($)	Mar. 04, 2022 USD ($)	Jul. 16, 2021 USD ($)	Jul. 15, 2021 USD ($)	Nov. 05, 2018 item	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
COMMITMENTS AND CONTINGENCIES
Royalty expense						$ 6.4	$ 9.0	$ 19.5	$ 25.0
Compensatory damages	$ 7.7	$ 1.8	$ 25.0	$ 7.7
Award to cover inconvenience and aggravation	$ 25.0
Accrued amount						0.2		0.2		$ 0.8
Accrued loss recovery asset						3.1		3.1
Number of raw coal storage silos, failure \| item					1
Number of raw coal storage silos \| item					3
Percentage of structural failure					80.00%
Surety Bond
COMMITMENTS AND CONTINGENCIES
Asset Retirement Obligation						31.2		31.2
Take-or-pay Purchase Commitments
COMMITMENTS AND CONTINGENCIES
Commitment						17.5		17.5
Total commitment								19.6
Environmental
COMMITMENTS AND CONTINGENCIES
Environmental liabilities						$ 0.0		$ 0.0