Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventories
Coal	$ 99,174	$ 96,954
Repair parts and supplies	145,087	126,061
Inventories	244,261	223,015
Allowance for slow-moving and obsolete inventories	$ 1,600	$ 2,400

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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- References

No definition available.

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- Definition

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

+ References

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-Topic 852
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- Definition

Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date for elements of machinery or equipment held for the purpose of replacing similar parts in the course of repair or maintenance.

+ References

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- Definition

Amount of valuation reserve for inventory.

+ References

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