Utility Rate Regulation (Regulatory Matters) (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013 Integer Y	Dec. 31, 2012
Regulatory Matters - Pennsylvania Activities - Storm Damage Expense Rider (Numeric) [Abstract]
Maximum period to file proposed Storm Damage Expense Rider (in days)		90
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 - Federal Matters - Federal Energy Regulatory Commission Formula Rates (Numeric) [Abstract]
Minimum pre-tax amount revenue could be negatively impacted by a formula rate recalculation		$ 0
Maximum pre-tax amount revenue could be negatively impacted by a formula rate recalculation		40,000,000
Regulatory Matters - United Kingdom Activities - Ofgem Review of Line Loss Calculation (Numeric) [Abstract]
Charge to income during period for line loss incentive/penalty liability	24,000,000	24,000,000
Minimum potential loss exposure regarding line loss incentive/penalty	97,000,000	97,000,000
Maximum potential loss exposure regarding line loss incentive/penalty	251,000,000	251,000,000
Liability at period end regarding line loss incentive/penalty	97,000,000	97,000,000	94,000,000
Reduction in liability for line loss liability, beginning April 2013, resulting refunds included in tariff		16,000,000
PPL Electric [Member] | Distribution Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		71,000,000
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		34,000,000
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		15,000,000
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		51,000,000
Return on equity used in approved rate case proceeding		10.25%
PPL Electric Utilities Corp [Member]
Regulatory Matters - Pennsylvania Activities - Storm Damage Expense Rider (Numeric) [Abstract]
Maximum period to file proposed Storm Damage Expense Rider (in days)		90
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 - Federal Matters - Federal Energy Regulatory Commission Formula Rates (Numeric) [Abstract]
Minimum pre-tax amount revenue could be negatively impacted by a formula rate recalculation		0
Maximum pre-tax amount revenue could be negatively impacted by a formula rate recalculation		40,000,000
PPL Electric Utilities Corp [Member] | Distribution Rates [Member]
Regulatory Matters - Rate Case Proceeding (Numeric) [Abstract]
Dollar amount of increase to rates		71,000,000
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		34,000,000
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		15,000,000
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		51,000,000
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		34,000,000
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		15,000,000
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		$ 51,000,000
Return on equity used in approved rate case proceeding		10.25%