Note 8 - Revenue (Tables)

6 Months Ended

Jun. 30, 2022

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Three months ended June 30,				Six months ended June 30,
(In thousands)	2022		2021		2022		2021
Coal Sales
North American revenue	$	91,397	$	37,550	$	150,629	$	57,656
Export revenue, excluding Canada		47,258		38,507		142,908		61,855
Total revenue	$	138,655	$	76,057	$	293,537	$	119,511