v3.26.1
Derivative Instruments and Hedging Activities - Gains and Losses - IS (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Not Designated As Hedging Instruments [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized in income on derivative $ (2) $ 0 $ 5 $ (5)
Gain (loss) recognized as regulatory liabilities/assets (9) (14) (10) 4
Interest Rate Swaps [Member] | Not Designated As Hedging Instruments [Member] | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized as regulatory liabilities/assets 1 (1) 1 (2)
Interest Rate Swaps [Member] | Cash Flow Hedges [Member] | Income Statement Location [Axis]: us-gaap:InterestExpense        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (Loss) Reclassified from AOCI into Income 0 (1) (1) (2)
Amount of gain (loss) reclassified from AOCI to income 0 (1) (1) (2)
Gas Contracts | Not Designated As Hedging Instruments [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized in income on derivative   $ 0   (5)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]   Energy purchases    
Gas Contracts | Not Designated As Hedging Instruments [Member] | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized as regulatory liabilities/assets (10) $ (1) (11) 0
Gas Contracts | Not Designated As Hedging Instruments [Member] | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryLiabilityCurrent        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized as regulatory liabilities/assets   $ (12)   $ 6
Gas Contracts | Income Statement Location [Axis]: us-gaap:OtherNonoperatingIncomeExpense | Not Designated As Hedging Instruments [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized in income on derivative 0   (1)  
Gas Contracts | Income Statement Location [Axis]: ppl:PurchasedPowerAndGas | Not Designated As Hedging Instruments [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized in income on derivative $ (2)   $ 6