Note 2 - Inventory	12 Months Ended
Dec. 31, 2023
Notes to Financial Statements
Inventory Disclosure [Text Block]	(2) INVENTORY Inventory is valued at lower of cost or net realizable value (“NRV”). As of December 31, 2023, and 2022, coal inventory includes NRV adjustments of $2.0 million and $4.9 million, respectively.

The entire disclosure for inventory. Includes, but is not limited to, the basis of stating inventory, the method of determining inventory cost, the classes of inventory, and the nature of the cost elements included in inventory.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 330
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//330/tableOfContent

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