Commitments and Contingencies (Environmental Matter and Other) (Details) - Integer	9 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Environmental Matters - Domestic - Air (Numeric) [Abstract]
Number of criteria pollutants	6
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Minimum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	3 years
Maximum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	10 years
Subsequent Event [Member]
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Percentage reduction in emissions rates below 2012 emission rates under the rate-based approach		41.00%
Percentage reduction in emissions rates below 2012 emission rates under the mass-based approach		36.00%
LG And E And KU Energy LLC [Member]
Environmental Matters - Domestic - Air (Numeric) [Abstract]
Number of criteria pollutants	6
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Minimum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	3 years
Maximum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	10 years
LG And E And KU Energy LLC [Member] | Subsequent Event [Member]
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Percentage reduction in emissions rates below 2012 emission rates under the rate-based approach		41.00%
Percentage reduction in emissions rates below 2012 emission rates under the mass-based approach		36.00%
Louisville Gas And Electric Co [Member]
Environmental Matters - Domestic - Air (Numeric) [Abstract]
Number of criteria pollutants	6
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Minimum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	3 years
Maximum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	10 years
Louisville Gas And Electric Co [Member] | Subsequent Event [Member]
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Percentage reduction in emissions rates below 2012 emission rates under the rate-based approach		41.00%
Percentage reduction in emissions rates below 2012 emission rates under the mass-based approach		36.00%
Kentucky Utilities Co [Member]
Environmental Matters - Domestic - Air (Numeric) [Abstract]
Number of criteria pollutants	6
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Number of electric utility companies affected by a September 2009 U.S. Court of Appeals for the Second Circuit decision	5
Environmental Matters - Domestic - Water/Waste - Coal Combustion Residuals (Numeric) [Abstract]
Minimum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	3 years
Maximum period to commence or complete closure activities under certain activities for coal combustion residuals (in years)	10 years
Kentucky Utilities Co [Member] | Subsequent Event [Member]
Environmental Matters - Domestic - Air - Climate Change - The EPA's Clean Power Plan (Numeric) [Abstract]
Percentage reduction in emissions rates below 2012 emission rates under the rate-based approach		41.00%
Percentage reduction in emissions rates below 2012 emission rates under the mass-based approach		36.00%