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Note 1 - General Business (Details Textual) | 6 Months Ended
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Jun. 30, 2024
Number of Reportable Segments | 2
Southwestern Indiana [Member] |
Number of Underground Mines Included in the Significant Operating Segment | 2
Sunrise Energy, LLC [Member] |
Equity Method Investment, Ownership Percentage | 50.00%

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- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 + Details
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