Utility Rate Regulation (Regulatory Matters) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Integer Y	Dec. 31, 2012
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Under Act 129, percentage cap on costs that can be recovered for implementation of EE and C plan		2.00%
Under Act 129, percentage reduction in electricity consumption by 2011		1.00%
Under Act 129, percentage reduction in electricity consumption by 2013		3.00%
Under Act 129, percentage reduction in peak demand electricity consumption by 2013		4.50%
Number of hours that are the benchmark for demand reductions by 2013		100
Number of years EDCs have to comply with consumption reduction target		3
Under Act 129, percentage reduction in electricity target for the company under the Phase II program		2.10%
Minimum term of long term supply contract under Act 129 (in years)		4
Maximum term of long term supply contract under Act 129 (in years)		20
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129		25.00%
Regulatory Matters - Pennsylvania Activities - Smart Meter Rider (Numeric) [Abstract]
Maximum number of years the cost of smart meters can be depreciated		15
Regulatory Matters - Pennsylvania Activities - Public Utility Commission Investigation of Retail Electricity Market (Numeric) [Abstract]
Number of phases of a PUC investigation of retail electricity market		2
Regulatory Matters - Pennsylvania Activities - Distribution System Improvement Charge (Numeric) [Abstract]
Number of ratemaking mechanisms authorized for PUC approval		2
Minimum term for Long Term Infrastructure Improvement Plan (in years)		5
Maximum term for Long Term Infrastructure Improvement Plan (in years)		10
Number of issues assigned to the Office of Administrative Law Judge		4
Regulatory Matters - United Kingdom Activities - Ofgem Review of Line Loss Calculation (Numeric) [Abstract]
Charge to income during period for line loss incentive/penalty liability	$ 21	$ 45
Minimum potential loss exposure regarding line loss incentive/penalty	93	93
Maximum potential loss exposure regarding line loss incentive/penalty	226	226
Liability at period end regarding line loss incentive/penalty	93	93	94
Reduction in liability for line loss liability, beginning April 2013, resulting refunds included in tariff		41
PPL Electric [Member] | Distribution Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		71
Return on equity used in approved rate case proceeding		10.40%
LGE [Member] | Electric Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		34
Return on equity used in approved rate case proceeding		10.25%
LGE [Member] | Gas Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		15
Return on equity used in approved rate case proceeding		10.25%
KU [Member] | Electric Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		51
Return on equity used in approved rate case proceeding		10.25%
PPL Electric Utilities Corp [Member]
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Under Act 129, percentage cap on costs that can be recovered for implementation of EE and C plan		2.00%
Under Act 129, percentage reduction in electricity consumption by 2011		1.00%
Under Act 129, percentage reduction in electricity consumption by 2013		3.00%
Under Act 129, percentage reduction in peak demand electricity consumption by 2013		4.50%
Number of hours that are the benchmark for demand reductions by 2013		100
Number of years EDCs have to comply with consumption reduction target		3
Under Act 129, percentage reduction in electricity target for the company under the Phase II program		2.10%
Minimum term of long term supply contract under Act 129 (in years)		4
Maximum term of long term supply contract under Act 129 (in years)		20
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129		25.00%
Regulatory Matters - Pennsylvania Activities - Smart Meter Rider (Numeric) [Abstract]
Maximum number of years the cost of smart meters can be depreciated		15
Regulatory Matters - Pennsylvania Activities - Public Utility Commission Investigation of Retail Electricity Market (Numeric) [Abstract]
Number of phases of a PUC investigation of retail electricity market		2
Regulatory Matters - Pennsylvania Activities - Distribution System Improvement Charge (Numeric) [Abstract]
Number of ratemaking mechanisms authorized for PUC approval		2
Minimum term for Long Term Infrastructure Improvement Plan (in years)		5
Maximum term for Long Term Infrastructure Improvement Plan (in years)		10
Number of issues assigned to the Office of Administrative Law Judge		4
PPL Electric Utilities Corp [Member] | Distribution Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		71
Return on equity used in approved rate case proceeding		10.40%
LG And E And KU Energy LLC [Member] | LGE [Member] | Electric Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		34
Return on equity used in approved rate case proceeding		10.25%
LG And E And KU Energy LLC [Member] | LGE [Member] | Gas Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		15
Return on equity used in approved rate case proceeding		10.25%
LG And E And KU Energy LLC [Member] | KU [Member] | Electric Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		51
Return on equity used in approved rate case proceeding		10.25%
Louisville Gas And Electric Co [Member] | Electric Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		34
Return on equity used in approved rate case proceeding		10.25%
Louisville Gas And Electric Co [Member] | Gas Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		15
Return on equity used in approved rate case proceeding		10.25%
Kentucky Utilities Co [Member] | Electric Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		$ 51
Return on equity used in approved rate case proceeding		10.25%