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v3.23.1

Note 1 - General Business (Details Textual) | 3 Months Ended
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Mar. 31, 2023
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 Represents the number of underground mines that are included in the significant operating segment. + References No definition available. + Details
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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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- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-18 + Details
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