SEGMENTS OF BUSINESS - Schedule of EBITDA Margin to Income (loss) before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
SEGMENTS OF BUSINESS
Income (Loss) before Income Taxes	$ (9,825)	$ 9,979
Other operating revenue	(1,631)	(1,596)
Depreciation, depletion and amortization	10,606	14,977
ARO accretion	408	427
Exploration costs	84	21
Gain on disposal or abandonment of assets, net	(201)	(21)
Interest income	(147)	(63)
Interest expense	3,970	3,723
Loss on extinguishment of debt	230
Equity method investment (loss)	121	236
Corporate - general and administrative	3,337	2,977
Segment EBITDA	6,952	30,660
Operating Segment | Electric Operations
SEGMENTS OF BUSINESS
Income (Loss) before Income Taxes	(5,038)	19,217
Other operating revenue	(137)	(87)
Depreciation, depletion and amortization	6,383	5,161
ARO accretion	131	120
Interest income	(36)
Interest expense	2,947	1,732
Segment EBITDA	4,250	26,143
Operating Segment | Coal Operations
SEGMENTS OF BUSINESS
Income (Loss) before Income Taxes	(2,979)	(5,082)
Other operating revenue	(1,140)	(1,261)
Depreciation, depletion and amortization	4,204	9,797
ARO accretion	277	307
Exploration costs	84	21
Gain on disposal or abandonment of assets, net	(201)	(21)
Interest income	(111)	(63)
Interest expense	808	1,991
Segment EBITDA	942	5,689
Corporate and Other and Eliminations
SEGMENTS OF BUSINESS
Income (Loss) before Income Taxes	(1,808)	(4,156)
Other operating revenue	(354)	(248)
Depreciation, depletion and amortization	19	19
Interest expense	215
Loss on extinguishment of debt	230
Equity method investment (loss)	121	236
Corporate - general and administrative	3,337	2,977
Segment EBITDA	$ 1,760	$ (1,172)