v3.26.1
DERIVATIVE INSTRUMENTS - GAINS (LOSSES) AND NOTIONAL VOLUMES (Details)
MWh in Millions, MMBTU in Millions, $ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
MWh
MMBTU
Jun. 30, 2025
USD ($)
MMBTU
MWh
Jun. 30, 2026
USD ($)
MMBTU
MWh
Jun. 30, 2025
USD ($)
MWh
MMBTU
Realized gains and losses        
Realized gains and losses on derivatives income statement location Cost of sales Cost of sales Cost of sales Cost of sales
Gains (losses) $ (1.6) $ 5.9 $ 7.7 $ 8.4
Natural gas contracts        
Realized gains and losses        
Gains (losses) $ (5.4) $ 4.6 $ 4.0 $ 6.1
Notional volumes        
Notional volumes | MMBTU 17.7 19.1 36.6 37.3
FTRs        
Realized gains and losses        
Gains (losses) $ 3.8 $ 1.3 $ 3.7 $ 2.3
Notional volumes        
Notional volumes | MWh 4.3 4.6 8.1 9.3