Note 2 - Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Restricted Cash
Restricted Cash	$ 800	$ 800
Restricted Cash, Statement of Financial Position [Extensible Enumeration]	Other Assets, Noncurrent	Other Assets, Noncurrent
Inventories
Raw coal	$ 19,709	$ 20,122
Saleable coal	17,969	12,013
Supplies	5,680	5,028
Total inventories	$ 43,358	$ 37,163