Note 8 - Revenues (Tables)

9 Months Ended

Sep. 30, 2020

Revenue from Contract with Customer [Abstract]

Schedule of disaggregation of revenue

	Three months ended September 30,				Nine months ended September 30,
(In thousands)	2020		2019		2020		2019
Coal Sales
Domestic revenues	$	13,546	$	50,382	$	64,764	$	126,498
Export revenues		25,913		10,998		53,005		58,103
Total revenues	$	39,459	$	61,380	$	117,769	$	184,601