Utility Rate Regulation (Regulatory Assets and Liabilities) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ (13)	$ 12	$ 59
Accounting Standards Update 2017-07 [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Assets	1
Accounting Standards Update 2017-07 [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Liabilities	$ 11
Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	15 years
Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 2,185	2,185
PPL Electric [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2021
Regulatory Assets and Liabilities - Storm Costs (Numeric) [Abstract]
Period over which storm costs will be recovered (in years)	3 years
PPL Electric [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2029
PPL Electric [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	5 years
PPL Electric [Member] | Storm Damage Expense Rider [Member]
Regulatory Assets and Liabilities - Storm Damage Expense Rider (Numeric) [Abstract]
Maximum reportable storm damage expenses to be recovered annually through base rates	$ 20
PPL Electric [Member] | Act 129 Compliance Rider [Member]
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum amount of costs that can be recovered under the Act 129 Phase III plan	$ 313
Period over which program costs can be recovered for Phase III (in years)	5 years
LKE [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 45	33
LKE [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2044
LKE [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Mar. 31, 2026
LGE [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2044
LGE [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
LGE [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2033
LGE [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity	9.70%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program	5 years
LGE [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	18 months
LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Return on equity	9.70%
KU [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Number of Municipal Customers | Customer	10
KU [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2042
KU [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Return on equity	9.70%
PPL Electric Utilities Corp [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	5 years
Increase (Decrease) in Regulatory Assets and Liabilities	$ 19	5	62
PPL Electric Utilities Corp [Member] | Accounting Standards Update 2017-07 [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Liabilities	$ 5
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2021
Regulatory Assets and Liabilities - Storm Costs (Numeric) [Abstract]
Period over which storm costs will be recovered (in years)	3 years
PPL Electric Utilities Corp [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2029
PPL Electric Utilities Corp [Member] | Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	5 years
PPL Electric Utilities Corp [Member] | Storm Damage Expense Rider [Member]
Regulatory Assets and Liabilities - Storm Damage Expense Rider (Numeric) [Abstract]
Maximum reportable storm damage expenses to be recovered annually through base rates	$ 20
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum amount of costs that can be recovered under the Act 129 Phase III plan	$ 313
Period over which program costs can be recovered for Phase III (in years)	5 years
PPL Electric Utilities Corp [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 1,019	1,019
LG And E And KU Energy LLC [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	(32)	7	(1)
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps	0	0	(9)
LG And E And KU Energy LLC [Member] | Accounting Standards Update 2017-07 [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Liabilities	6
Regulatory Assets	$ 1
LG And E And KU Energy LLC [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 45	33
LG And E And KU Energy LLC [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2044
LG And E And KU Energy LLC [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Mar. 31, 2026
LG And E And KU Energy LLC [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 1,166	1,166
LG And E And KU Energy LLC [Member] | LGE [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
LG And E And KU Energy LLC [Member] | LGE [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2033
LG And E And KU Energy LLC [Member] | LGE [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity	9.70%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program	5 years
LG And E And KU Energy LLC [Member] | LGE [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	18 months
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Return on equity	9.70%
LG And E And KU Energy LLC [Member] | KU [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Number of Municipal Customers | Customer	10
LG And E And KU Energy LLC [Member] | KU [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
LG And E And KU Energy LLC [Member] | KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Return on equity	9.70%
Louisville Gas And Electric Co [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ (5)	5	1
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps	0	0	(9)
Louisville Gas And Electric Co [Member] | Accounting Standards Update 2017-07 [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Assets	$ 1
Louisville Gas And Electric Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 25	18
Louisville Gas And Electric Co [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2044
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Louisville Gas And Electric Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2033
Louisville Gas And Electric Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Mar. 31, 2026
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity	9.70%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program	5 years
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	18 months
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Return on equity	9.70%
Louisville Gas And Electric Co [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 532	532
Kentucky Utilities Co [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Number of Municipal Customers | Customer	10
Increase (Decrease) in Regulatory Assets and Liabilities	$ (27)	2	$ (2)
Kentucky Utilities Co [Member] | Accounting Standards Update 2017-07 [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Liabilities	$ 6
Kentucky Utilities Co [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	15 years
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period	$ 20	15
Kentucky Utilities Co [Member] | Unamortized loss on debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Dec. 31, 2042
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Kentucky Utilities Co [Member] | Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date	Mar. 31, 2026
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period	12 months
Return on equity	9.70%
Kentucky Utilities Co [Member] | Tax Cuts And Jobs Act [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 634	$ 634