Note 3 - Other Long-term Assets (In Thousands) (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Schedule of Other Assets, Noncurrent [Table Text Block]

	December 31,
	2023		2022
Advanced coal royalties	$	5,521	$	5,967
Other		1,540		1,618
Total other assets	$	7,061	$	7,585