Note 11 - Revenue - Domestic Revenues an Export Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
REVENUES
Revenues	$ 693,524	$ 565,688	$ 283,394
CANADA
REVENUES
Percentage of Sales	14.00%	12.00%
SOUTH AFRICA
REVENUES
Percentage of Sales		10.00%
GERMANY
REVENUES
Percentage of Sales	14.00%
BRAZIL
REVENUES
Percentage of Sales	10.00%
Domestic Coal Revenues
REVENUES
Revenues	$ 227,484	$ 328,322	143,946
Foreign Coal Revenues
REVENUES
Percentage of Sales	10.00%
Export Revenues
REVENUES
Revenues	$ 466,040	$ 237,366	$ 139,448