Note 4 - Other Long-term Assets (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Other Assets, Noncurrent [Table Text Block]

	December 31,
	2022		2021
Advanced coal royalties	$	5,967	$	6,678
Other		1,618		1,694
Total other assets	$	7,585	$	8,372