Note 4 - Debt - Summary of Outstanding Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Total debt	$ 86,378	$ 90,179
Current portion long term debt	28,227	56,534
Long-term debt, net	58,151	33,645
Revolving Credit Facility
Total debt	41,500	42,500
Current portion long term debt	17,000
Equipment loans
Total debt	2,466	2,983
Current portion long term debt	2,200
Senior Notes, net
Total debt	33,412	33,296
Maben Coal LLC
Total debt	9,000	$ 11,400
Current portion long term debt	$ 9,000

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-4

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant