Note 11 - Revenue - Domestic Revenues an Export Revenues (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / T	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
REVENUES
Revenues	$ 565,688	$ 283,394	$ 168,915	$ 168,915
CANADA
REVENUES
Percentage of Sales	12.00%
SOUTH AFRICA
REVENUES
Percentage of Sales	10.00%
Domestic Coal Revenues
REVENUES
Revenues	$ 328,322	143,946		119,981
Export Revenues
REVENUES
Revenues	$ 237,366	$ 139,448		$ 48,934
Percentage of Sales	10.00%
Fixed Priced Contracts
REVENUES
Average per ton | $ / T	202