v3.26.1
PROPERTY, PLANT, AND EQUIPMENT - Narrative (Details) - USD ($)
$ in Millions
Nov. 07, 2025
Dec. 31, 2025
Mar. 17, 2025
Dec. 31, 2024
PROPERTY, PLANT AND EQUIPMENT        
Government assistance, award amount     $ 6.1  
Qualifying costs   $ 0.5    
Offset to Property, plant and equipment, net   0.4    
Other income   0.1    
Mining property and mineral rights        
PROPERTY, PLANT AND EQUIPMENT        
Purchase price $ 15.0      
Transaction costs $ 0.3      
Coal Properties        
PROPERTY, PLANT AND EQUIPMENT        
Capitalized amounts related to coal reserves   $ 18.5   $ 16.2