v3.26.3
Risk Management Activities (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Balance Sheet Location [Axis]: us-gaap:OtherAssetsCurrent    
Derivatives, Fair Value [Line Items]    
Risk management assets $ 1.3 $ 9.7
Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesCurrent    
Derivatives, Fair Value [Line Items]    
Risk management liabilities 6.4 2.1
Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Risk management assets 9.3 9.1
Risk management liabilities 6.7 3.8
Commodity Price Risk Programs | Balance Sheet Location [Axis]: us-gaap:OtherAssetsCurrent    
Derivatives, Fair Value [Line Items]    
Risk management assets 1.3 9.7
Commodity Price Risk Programs | Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesCurrent    
Derivatives, Fair Value [Line Items]    
Risk management liabilities 6.4 2.1
Commodity Price Risk Programs | Balance Sheet Location [Axis]: us-gaap:OtherLiabilitiesNoncurrent    
Derivatives, Fair Value [Line Items]    
Risk management assets 9.3 9.1
Risk management liabilities $ 6.7 $ 3.8