Commitments and Contingencies (Environmental Matter and Other) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 lb T Y Integer	Dec. 31, 2013 T
Environmental Matters - Domestic - Air - Cross State Air Pollution Rule (formerly Clean Air Transport Rule) and Clean Air Interstate Rule (Numeric) [Abstract]
Number of phases CSAPR will be implemented	2
Environmental Matters - Domestic - Air - Mercury and Air Toxics (Numeric) [Abstract]
Period for compliance with final MACT standards (in years)	3
Possible period of extension to comply with final MACT standards (in years)	1
Environmental Matters - Domestic - Air - Greenhouse Gas Regulations and Tort Litigation (Numeric) [Abstract]
Percentage reduction of greenhouse gas emissions below 2005 levels by 2020	17.00%
Estimate of "social cost of carbon" per metric ton prior to 2015	23.8
Estimate of "social cost of carbon" per metric ton in 2015	38
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Number of companies cited in May 2011 Mississippi court filing	87
Number of indirect subsidaries cited in a May 2011 Mississippi court filing	3
Carbon dioxide emitted from PPL power plants during the reporting period (in tons)	62,000,000	62,000,000
Number of pounds in a ton of carbon dioxide emissions	2,000
Environmental Matters - Domestic - Air - Renewable Energy Legislation (Numeric) [Abstract]
Proposed percentage of New Jersey renewable energy portfolio standard by 2020	30.00%
Proposed percentage of New Jersey renewable energy portfolio standard by 2050	80.00%
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Number of approaches proposed by EPA in June 2010 to regulate CCRs	2
Environmental Matters - Domestic - Water/Waste - Seepages and Groundwater Infiltration - Pennsylvania, Montana and Kentucky (Numeric) [Abstract]
Period for PPL Montana to provide financial assurance to Montana Department of Environmental Quality (in years)	5
Environmental Matters - Domestic - Superfund and Other Remediation (Numeric) [Abstract]
Period end recorded discounted liability for the cost of pumping and treating groundwater, and operating and maintaining a passive wetlands treatment center	$ 19,000,000
Period of years used to calculate discounted environmental liability	50
Weighted average discount rate applied to calculate the liability (in hundredths)	8.41%
Expected undiscounted payments per year related to pumping and treating groundwater, and operating and maintaining a passive wetlands treatment center after 2019	93,000,000
Other - Nuclear Insurance (Numeric) [Abstract]
Maximum public liability for claims resulting an incident at nuclear station	13,600,000,000
Maximum amount that could be assessed resulting from an incident at nuclear station	255,000,000
Maximum amount payable per year resulting from an incident at nuclear station	38,000,000
Maximum amount of insured property damage losses at nuclear station	2,000,000,000
Maximum assessment for retroactive premiums for nuclear outage insurance coverage	46,000,000
International Brotherhood Of Electrical Workers Local 1600 [Member]
Other - Labor Union Agreements (Details) [Line Items]
Term, in years, of newly approved labor agreement	3
Pension benefits recorded related to voluntary retirement election	13,000,000
Severance compensation recorded related to voluntary retirement election	7,000,000
Total seperation benefits recorded related to voluntary retirement election	20,000,000
Number of employees who elected voluntary retirement	123
PPL Energy Supply LLC [Member]
Environmental Matters - Domestic - Air - Cross State Air Pollution Rule (formerly Clean Air Transport Rule) and Clean Air Interstate Rule (Numeric) [Abstract]
Number of phases CSAPR will be implemented	2
Environmental Matters - Domestic - Air - Mercury and Air Toxics (Numeric) [Abstract]
Period for compliance with final MACT standards (in years)	3
Possible period of extension to comply with final MACT standards (in years)	1
Environmental Matters - Domestic - Air - Greenhouse Gas Regulations and Tort Litigation (Numeric) [Abstract]
Percentage reduction of greenhouse gas emissions below 2005 levels by 2020	17.00%
Estimate of "social cost of carbon" per metric ton prior to 2015	23.8
Estimate of "social cost of carbon" per metric ton in 2015	38
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Number of companies cited in May 2011 Mississippi court filing	87
Carbon dioxide emitted from PPL power plants during the reporting period (in tons)	26,000,000
Number of pounds in a ton of carbon dioxide emissions	2,000
Environmental Matters - Domestic - Air - Renewable Energy Legislation (Numeric) [Abstract]
Proposed percentage of New Jersey renewable energy portfolio standard by 2020	30.00%
Proposed percentage of New Jersey renewable energy portfolio standard by 2050	80.00%
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Number of approaches proposed by EPA in June 2010 to regulate CCRs	2
Environmental Matters - Domestic - Water/Waste - Seepages and Groundwater Infiltration - Pennsylvania, Montana and Kentucky (Numeric) [Abstract]
Period for PPL Montana to provide financial assurance to Montana Department of Environmental Quality (in years)	5
Environmental Matters - Domestic - Superfund and Other Remediation (Numeric) [Abstract]
Period end recorded discounted liability for the cost of pumping and treating groundwater, and operating and maintaining a passive wetlands treatment center	19,000,000
Period of years used to calculate discounted environmental liability	50
Weighted average discount rate applied to calculate the liability (in hundredths)	8.41%
Expected undiscounted payments per year related to pumping and treating groundwater, and operating and maintaining a passive wetlands treatment center after 2019	93,000,000
Other - Nuclear Insurance (Numeric) [Abstract]
Maximum public liability for claims resulting an incident at nuclear station	13,600,000,000
Maximum amount that could be assessed resulting from an incident at nuclear station	255,000,000
Maximum amount payable per year resulting from an incident at nuclear station	38,000,000
Maximum amount of insured property damage losses at nuclear station	2,000,000,000
Maximum assessment for retroactive premiums for nuclear outage insurance coverage	46,000,000
PPL Energy Supply LLC [Member] | International Brotherhood Of Electrical Workers Local 1600 [Member]
Other - Labor Union Agreements (Details) [Line Items]
Term, in years, of newly approved labor agreement	3
Pension benefits recorded related to voluntary retirement election	11,000,000
Severance compensation recorded related to voluntary retirement election	6,000,000
Total seperation benefits recorded related to voluntary retirement election	17,000,000
Number of employees who elected voluntary retirement	105
PPL Electric Utilities Corp [Member] | International Brotherhood Of Electrical Workers Local 1600 [Member]
Other - Labor Union Agreements (Details) [Line Items]
Term, in years, of newly approved labor agreement	3
Pension benefits recorded related to voluntary retirement election	2,000,000
Severance compensation recorded related to voluntary retirement election	1,000,000
Total seperation benefits recorded related to voluntary retirement election	$ 3,000,000
Number of employees who elected voluntary retirement	17
LG And E And KU Energy LLC [Member]
Environmental Matters - Domestic - Air - Cross State Air Pollution Rule (formerly Clean Air Transport Rule) and Clean Air Interstate Rule (Numeric) [Abstract]
Number of phases CSAPR will be implemented	2
Environmental Matters - Domestic - Air - Mercury and Air Toxics (Numeric) [Abstract]
Period for compliance with final MACT standards (in years)	3
Possible period of extension to comply with final MACT standards (in years)	1
Environmental Matters - Domestic - Air - Greenhouse Gas Regulations and Tort Litigation (Numeric) [Abstract]
Percentage reduction of greenhouse gas emissions below 2005 levels by 2020	17.00%
Estimate of "social cost of carbon" per metric ton prior to 2015	23.8
Estimate of "social cost of carbon" per metric ton in 2015	38
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Number of companies cited in May 2011 Mississippi court filing	87
Number of indirect subsidaries cited in a May 2011 Mississippi court filing	3
Number of pounds in a ton of carbon dioxide emissions	2,000
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Number of approaches proposed by EPA in June 2010 to regulate CCRs	2
Louisville Gas And Electric Co [Member]
Environmental Matters - Domestic - Air - Cross State Air Pollution Rule (formerly Clean Air Transport Rule) and Clean Air Interstate Rule (Numeric) [Abstract]
Number of phases CSAPR will be implemented	2
Environmental Matters - Domestic - Air - Mercury and Air Toxics (Numeric) [Abstract]
Period for compliance with final MACT standards (in years)	3
Possible period of extension to comply with final MACT standards (in years)	1
Environmental Matters - Domestic - Air - Greenhouse Gas Regulations and Tort Litigation (Numeric) [Abstract]
Percentage reduction of greenhouse gas emissions below 2005 levels by 2020	17.00%
Estimate of "social cost of carbon" per metric ton prior to 2015	23.8
Estimate of "social cost of carbon" per metric ton in 2015	38
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Number of companies cited in May 2011 Mississippi court filing	87
Carbon dioxide emitted from LKE power plants during the reporting period (in tons)	18,000,000
Number of pounds in a ton of carbon dioxide emissions	2,000
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Number of approaches proposed by EPA in June 2010 to regulate CCRs	2
Kentucky Utilities Co [Member]
Environmental Matters - Domestic - Air - Cross State Air Pollution Rule (formerly Clean Air Transport Rule) and Clean Air Interstate Rule (Numeric) [Abstract]
Number of phases CSAPR will be implemented	2
Environmental Matters - Domestic - Air - Mercury and Air Toxics (Numeric) [Abstract]
Period for compliance with final MACT standards (in years)	3
Possible period of extension to comply with final MACT standards (in years)	1
Environmental Matters - Domestic - Air - Greenhouse Gas Regulations and Tort Litigation (Numeric) [Abstract]
Percentage reduction of greenhouse gas emissions below 2005 levels by 2020	17.00%
Estimate of "social cost of carbon" per metric ton prior to 2015	23.8
Estimate of "social cost of carbon" per metric ton in 2015	38
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Number of companies cited in May 2011 Mississippi court filing	87
Carbon dioxide emitted from LKE power plants during the reporting period (in tons)	18,000,000
Number of pounds in a ton of carbon dioxide emissions	2,000
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Number of approaches proposed by EPA in June 2010 to regulate CCRs	2