v3.26.3
Derivative Instruments and Hedging Activities - Gains and Losses - IS (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Not Designated As Hedging Instruments [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized in income on derivative $ (2) $ (2) $ 3 $ (8)
Gain (loss) recognized as regulatory liabilities/assets (2) (9) (12) (5)
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 2 0 3 (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] | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsNoncurrent        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized as regulatory liabilities/assets (4) (6) (15) (6)
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   (3)   0
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 0 (1) (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) (2) $ 4 (7)
Gas Contract | Not Designated As Hedging Instruments [Member] | Location, Statement of Financial Position, Activity, Accrual [Axis]: us-gaap:RegulatoryAssetsCurrent        
Derivative Instruments, Gain (Loss) [Line Items]        
Gain (loss) recognized as regulatory liabilities/assets   $ 0   $ 3