Note 9 - Revenues (Tables)

6 Months Ended

Jun. 30, 2021

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Three months ended June 30,				Six months ended June 30,
(In thousands)	2021		2020		2021		2020
Coal Sales
North American revenues	$	37,550	$	31,005	$	57,656	$	62,510
Export revenues, excluding Canada		38,507		5,369		61,855		15,800
Total revenues	$	76,057	$	36,374	$	119,511	$	78,310