Note 18 - Segment of Business - Summary of Reportable Segments Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue	$ 361,991	$ 247,666
Operating Expense	30,430	(6,044)
Depreciation	46,875	39,973
Amount attributable to assets acquired	630,554	353,980
Capital Expenditures	54,020	28,050
Coal Operations [Member]
Revenue	293,344	246,396
Operating Expense	3,736	1,992
Depreciation	43,612	39,829
Amount attributable to assets acquired	376,228	346,201
Capital Expenditures	50,367	28,050
Electric Operations [Member]
Revenue	66,316	0
Operating Expense	31,505	0
Depreciation	3,117	0
Amount attributable to assets acquired	266,730	0
Capital Expenditures	3,653	0
Corporate and Other [Member]
Revenue	2,331	1,270
Operating Expense	(4,811)	(8,036)
Depreciation	146	144
Amount attributable to assets acquired	(12,404)	7,779
Capital Expenditures	$ 0	$ 0