Derivative Instruments and Hedging Activities (Risk Disclosures) (Details) $ in Millions, £ in Billions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 GBP (£)	Sep. 30, 2016 GBP (£)
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ (2)	$ 9	$ 101
Cash Flow Hedges [Member]
Interest Rate Risk - Cash Flow Hedges (Numeric) [Abstract]
Insignificant or no hedge ineffectiveness associated with interest rate cash flow hedges			For 2017, PPL had no hedge ineffectiveness associated with interest rate derivatives. For 2016 and 2015, hedge ineffectiveness associated with interest rate derivatives was insignificant.
No or insignificant after-tax gains (losses) previously recorded in AOCI reclassified to earnings related to interest rate cash flow hedge contracts			PPL had an insignificant amount of cash flow hedges reclassified into earnings associated with discontinued cash flow hedges in 2017 and 2016. As a result of the June 1, 2015 spinoff of PPL Energy Supply, all PPL cash flow hedges associated with PPL Energy Supply were ineffective and discontinued and therefore, reclassified into earnings during the second quarter of 2015 and reflected in discontinued operations for 2015. See Note 8 for additional information. PPL had no other cash flow hedges reclassified into earnings associated with discontinued cash flow hedges in 2015.
Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next 12 Months Insignificant			insignificant.
Cash Flow Hedges [Member] | Cross Currency Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	$ 702		$ 702
Interest Rate Risk - Cash Flow Hedges (Numeric) [Abstract]
Earliest maturity date of cross-currency cash flow hedge contracts			2021
Latest maturity date of cross-currency cash flow hedge contracts			2028
Repayment Of Senior Debt Related To Matured Cash Flow Hedge	100
Derivative, Notional Amount Matured	100		$ 100
Gain (loss) recognized in income upon settlement of cross-currency interest rate swap contracts			19
Economic Hedges [Member] | Foreign Currency Contracts [Member]
Foreign Currency Risk - Economic Activity (Numeric) [Abstract]
Total exposure hedged related to foreign currency contracts for anticipated earnings hedges classified as economic activity	3,500		$ 3,500			£ 2.6
Earliest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity			Jan. 31, 2018
Latest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity			Jun. 30, 2020
Economic Hedges [Member] | Foreign Currency Contracts [Member] | Hedges 2017 and 2018 [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount		$ 2,000					£ 1.3
Foreign Currency Risk - Economic Activity (Numeric) [Abstract]
Earliest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity		Jan. 31, 2017
Latest termination date of foreign currency contracts for anticipated earnings hedges classified as economic activity		Nov. 30, 2018
Derivative Cash Received On Hedge		$ 310
Net Investment Hedges [Member] | Foreign Currency Contracts [Member]
Foreign Currency Risk - Net Investment Hedges (Numeric) [Abstract]
Net after tax gains (losses) on net investment hedges recognized in the foreign currency translation adjustment component of AOCI			$ 22	21
LGE [Member] | Economic Hedges [Member] | Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	147		$ 147
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of terminated swaps				32
Net cash settlements on terminated interest rate swaps				9
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2033
LG And E And KU Energy LLC [Member]
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ 0	9	88
LG And E And KU Energy LLC [Member] | LGE [Member] | Economic Hedges [Member] | Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	147		$ 147
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of terminated swaps				32
Net cash settlements on terminated interest rate swaps				9
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2033
Louisville Gas And Electric Co [Member]
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ 0	9	44
Louisville Gas And Electric Co [Member] | Economic Hedges [Member] | Interest Rate Swaps [Member]
Interest Rate Risk And Foreign Currency Risk [Line Items]
Notional amount	$ 147		$ 147
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Notional amount of terminated swaps				32
Net cash settlements on terminated interest rate swaps				9
Year of expiration of the maximum maturity date of interest rate economic activity contracts			2033
Kentucky Utilities Co [Member]
Interest Rate Risk - Economic Activity (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ 0	$ 0	$ 44