Note 9 - Equity - Dividends (Details)	3 Months Ended	12 Months Ended
	Jun. 30, 2022 $ / T	Dec. 31, 2023
Price per ton of coal processed at preparation plants	5.00
Price per ton of loaded coal at rail load-out facilities	2.50
Percentage dividend from financial performance of carbon	20
Class B Common Stock
Percentage dividend from financial performance of carbon		20