XML 89 R9.htm IDEA: XBRL DOCUMENT v3.25.1
OTHER LONG-TERM ASSETS (IN THOUSANDS)
 12 Months Ended
Dec. 31, 2024
OTHER LONG-TERM ASSETS (IN THOUSANDS)  
OTHER LONG-TERM ASSETS (IN THOUSANDS)

(3)     OTHER LONG-TERM ASSETS (IN THOUSANDS)

​

​

​

​

​

​

​

​

​

    

December 31, 

​

    

2024

    

2023

Advanced coal royalties

​

$

3,906

​

$

5,521

Other

​

 

45

​

 

—

Total other assets

​

$

3,951

​

$

5,521

​