Note 8 - Revenue (Tables)

6 Months Ended

Jun. 30, 2023

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Three months ended June 30,				Six months ended June 30,
(In thousands)	2023		2022		2023		2022
Coal Sales
North American revenue	$	53,401	$	91,397	$	93,428	$	150,629
Export revenue, excluding Canada		84,068		47,258		210,401		142,908
Total revenue	$	137,469	$	138,655	$	303,829	$	293,537