INVENTORIES (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025	Dec. 31, 2024
INVENTORIES
Coal	$ 56,903	$ 37,290
Finished goods (net of reserve for obsolescence)	12,881	14,197
Work in process	1,332	1,560
Raw materials	7,930	7,192
Total operating inventories, net	79,046	60,239
Supplies (net of reserve for obsolescence)	59,740	60,422
Total inventories, net	138,786	120,661
Reduce inventory carrying value to market	5,700	24,600
Manufactured goods
INVENTORIES
Reserve for obsolescence	2,617	2,481
Supplies
INVENTORIES
Reserve for obsolescence	$ 6,562	$ 6,409

Carrying amount as of the balance sheet date of energy and manufactured goods inventory, net of reserves.

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- Definition

Carrying amount as of the balance sheet date of coal, which is a combustible rock or minerals which are extracted from the ground and used as fuel.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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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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No definition available.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of unprocessed items to be consumed in the manufacturing or production process.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of products used directly or indirectly in the manufacturing or production process, which may or may not become part of the final product. May also include items used in the storage, presentation or transportation of physical goods.

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Amount of valuation reserve for inventory.

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Carrying amount, net of reserves and adjustments, as of the balance sheet date of merchandise or goods which are partially completed. This inventory is generally comprised of raw materials, labor and factory overhead costs, which require further materials, labor and overhead to be converted into finished goods, and which generally require the use of estimates to determine percentage complete and pricing.

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Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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