Utility Rate Regulation (Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions		12 Months Ended
	Aug. 08, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2016	Sep. 30, 2015
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ (9)	$ (101)	$ 0
Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
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]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year		$ 58
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		20
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in 2017		$ 14
Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
Regulatory Assets and Liabilities - Storm Costs (Numeric) [Abstract]
Period over which storm costs will be recovered (in years)		3 years
Unamortized Loss On Debt [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2044
Accumulated Cost Of Removal Of Utility Plant [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		5 years
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		$ 15
Amount of amortized storm expense included in base rate component		$ 5
Act 129 Compliance Rider [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		3 years
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost		$ 250
Maximum recoverable cost Phase II		185
Maximum amount of costs that can be recovered under the Act 129 Phase III plan		$ 313
Period over which program costs can be recovered (in years)		5 years
Smart Meter Rider [Member]
Regulatory Assets and Liabilities - Smart Meter Rider (Numeric) [Abstract]
Maximum number of years the cost of smart meters can be depreciated		15 years
Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Period of recurring reviews of activity		six-month and two-year
Return on equity for approved projects remaining from earlier ECR plans		10.00%
Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		18 months
Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2033
Amortization end date for the deferred recovery of a regulatory liability		Dec. 31, 2043
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 9	(88)
Net cash settlements on terminated interest rate swaps					$ 86
Amortization end date for 2008 terminated swap contract		Dec. 31, 2035
Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity		10.00%
Regulatory Assets and Liabilities - Gas Line Tracker (Numeric) [Abstract]
Term, in years, of the gas service rider program		5 years
Asset Retirement Obligations [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
Asset Retirement Obligations [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
Coal Contracts [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2016
Power Purchase Agreement Ohio Valley Electric Corporation [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Mar. 31, 2026
Plant Retirement Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		3 years
Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity	9.80%
First Mortgage Bonds [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Principal amount							$ 1,050
PPL Electric [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 (in years)		5 years
PPL Electric Utilities Corp [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		5 years
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 (in years)		5 years
PPL Electric Utilities Corp [Member] | Defined Benefit Plans [Member]
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year		$ 25
PPL Electric Utilities Corp [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
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 Liability 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		$ 15
Amount of amortized storm expense included in base rate component		$ 5
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		3 years
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost		$ 250
Maximum recoverable cost Phase II		185
Maximum amount of costs that can be recovered under the Act 129 Phase III plan		$ 313
Period over which program costs can be recovered (in years)		5 years
PPL Electric Utilities Corp [Member] | Smart Meter Rider [Member]
Regulatory Assets and Liabilities - Smart Meter Rider (Numeric) [Abstract]
Maximum number of years the cost of smart meters can be depreciated		15 years
PPL Electric Utilities Corp [Member] | First Mortgage Bonds [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Principal amount						$ 224
LG And E And KU Energy LLC [Member]
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ (9)	(88)	0
LG And E And KU Energy LLC [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
LG And E And KU Energy LLC [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
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]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year		$ 33
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		$ 20
LG And E And KU Energy LLC [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
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] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Period of recurring reviews of activity		six-month and two-year
Return on equity for approved projects remaining from earlier ECR plans		10.00%
LG And E And KU Energy LLC [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		18 months
LG And E And KU Energy LLC [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
LG And E And KU Energy LLC [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2033
Amortization end date for the deferred recovery of a regulatory liability		Dec. 31, 2043
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 9	(88)
Net cash settlements on terminated interest rate swaps					86
Amortization end date for 2008 terminated swap contract		Dec. 31, 2035
LG And E And KU Energy LLC [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity		10.00%
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] | Asset Retirement Obligations [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
LG And E And KU Energy LLC [Member] | Asset Retirement Obligations [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
LG And E And KU Energy LLC [Member] | Coal Contracts [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2016
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] | Plant Retirement Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		3 years
LG And E And KU Energy LLC [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity	9.80%	9.80%
LG And E And KU Energy LLC [Member] | First Mortgage Bonds [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Principal amount							1,050
Louisville Gas And Electric Co [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		$ (5)	(3)
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ (9)	(44)	0
Louisville Gas And Electric Co [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
Louisville Gas And Electric Co [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
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]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year		$ 22
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		11
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in 2017		$ 8
Louisville Gas And Electric Co [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
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] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Period of recurring reviews of activity		six-month and two-year
Return on equity for approved projects remaining from earlier ECR plans		10.00%
Louisville Gas And Electric Co [Member] | Gas Supply Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		18 months
Louisville Gas And Electric Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability 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
Amortization end date for the deferred recovery of a regulatory liability		Dec. 31, 2043
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 9	(44)
Net cash settlements on terminated interest rate swaps					43
Amortization end date for 2008 terminated swap contract		Dec. 31, 2035
Louisville Gas And Electric Co [Member] | Gas Line Tracker [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity		10.00%
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] | Asset Retirement Obligations [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
Louisville Gas And Electric Co [Member] | Asset Retirement Obligations [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
Louisville Gas And Electric Co [Member] | Coal Contracts [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2016
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] | Plant Retirement Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		3 years
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Return on equity	9.80%	9.80%
Louisville Gas And Electric Co [Member] | First Mortgage Bonds [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Principal amount							550
Kentucky Utilities Co [Member]
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps		$ 0	(44)	$ 0
Kentucky Utilities Co [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
Kentucky Utilities Co [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
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]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year		$ 11
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period		9
Deferred recovery of the difference between pension costs calculated with pension accounting policy and pension cost using 15 year amortization period to be recorded as a regulatory asset in 2017		$ 6
Kentucky Utilities Co [Member] | Storm Costs [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date		Dec. 31, 2020
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] | Environmental Cost Recovery [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
Regulatory Assets and Liabilities - Environmental Cost Recovery (Numeric) [Abstract]
Period of recurring reviews of activity		six-month and two-year
Return on equity for approved projects remaining from earlier ECR plans		10.00%
Kentucky Utilities Co [Member] | Fuel Adjustment Clause [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Liability Amortization Period		12 months
Kentucky Utilities Co [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Amortization end date for the deferred recovery of a regulatory liability		Dec. 31, 2043
Regulatory Assets and Liabilities - Interest Rate Swaps (Numeric) [Abstract]
Net cash settlements on terminated interest rate swaps			$ (44)
Net cash settlements on terminated interest rate swaps					$ 43
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member] | Minimum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		10 years
Kentucky Utilities Co [Member] | Asset Retirement Obligations [Member] | Maximum [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Regulatory Asset Amortization Period		25 years
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]
Return on equity	9.80%	9.80%
Kentucky Utilities Co [Member] | First Mortgage Bonds [Member] | Interest Rate Swaps [Member]
Regulatory Assets and Liabilities (Numeric) [Line Items]
Principal amount							$ 500