Acquisitions, Development and Divestures (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013 mi kV Integer	Dec. 31, 2012
Other - Montana Transactions (Numeric) [Line Items]
Capacity of facilities to be sold (in MW)	633
Agreed upon sales price for disposal of hydroelectric facilities owned by PPL Montana	$ 900
Number of hydroelectric facilities owned by PPL Montana to be sold	11
Agreed upon amount to terminate a sale-leaseback arrangement by PPL Montana	271
Expected minimum amount of estimated loss on future sale-leaseback termination, after-tax	310
Expected maximum amount of estimated loss on future sale-leaseback termination, after-tax	430
Current book value of lease related assets on the balance sheet	450
Green River Plant [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	700
Expected capital cost of an expansion project	700
Solar Generation Facility [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	10
Expected capital cost of an expansion project	25
Proposed Bell Bend Nuclear Unit [Member]
Development Projects [Abstract]
Amount currently authorized by Board of Directors to spend on Bell Bend COLA	205
Capitalized costs associated with licensing efforts	169	154
Rainbow Hydroelectric Plant Expansion [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	63
Susquehanna Roseland Transmission Line [Member]
Development Projects [Abstract]
Expected capital cost of an expansion project	630
Total length (in miles) of the expansion project to be routed through Pennsylvania	101
Northeast Pocono Reliability Project [Member]
Development Projects [Abstract]
Expected capital cost of an expansion project	335	200
Total length (in miles) of the expansion project	58
Capacity (in kilovolts) of a transmission line	230
Number of new substations included in request	3
Adder to the return on equity incentive denied in ratemaking request (in basis points)	100
Zoning petitions to be approved	2
Project costs that qualify for the construction work in progress incentive	308
Ironwood [Member]
Business Acquisition [Line Items]
Acquisition date	Apr. 13, 2012
Lower Mount Bethel Plant [Member]
Business Acquisition [Line Items]
Purchase price at lease termination	455
PPL Energy Supply LLC [Member]
Other - Montana Transactions (Numeric) [Line Items]
Capacity of facilities to be sold (in MW)	633
Agreed upon sales price for disposal of hydroelectric facilities owned by PPL Montana	900
Number of hydroelectric facilities owned by PPL Montana to be sold	11
Agreed upon amount to terminate a sale-leaseback arrangement by PPL Montana	271
Expected minimum amount of estimated loss on future sale-leaseback termination, after-tax	310
Expected maximum amount of estimated loss on future sale-leaseback termination, after-tax	430
Current book value of lease related assets on the balance sheet	450
PPL Energy Supply LLC [Member] | Proposed Bell Bend Nuclear Unit [Member]
Development Projects [Abstract]
Amount currently authorized by Board of Directors to spend on Bell Bend COLA	205
Capitalized costs associated with licensing efforts	169	154
PPL Energy Supply LLC [Member] | Rainbow Hydroelectric Plant Expansion [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	63
PPL Energy Supply LLC [Member] | Ironwood [Member]
Business Acquisition [Line Items]
Acquisition date	Apr. 13, 2012
PPL Energy Supply LLC [Member] | Lower Mount Bethel Plant [Member]
Business Acquisition [Line Items]
Purchase price at lease termination	455
PPL Electric Utilities Corp [Member] | Susquehanna Roseland Transmission Line [Member]
Development Projects [Abstract]
Expected capital cost of an expansion project	630
Total length (in miles) of the expansion project to be routed through Pennsylvania	101
PPL Electric Utilities Corp [Member] | Northeast Pocono Reliability Project [Member]
Development Projects [Abstract]
Expected capital cost of an expansion project	335	200
Total length (in miles) of the expansion project	58
Capacity (in kilovolts) of a transmission line	230
Number of new substations included in request	3
Adder to the return on equity incentive denied in ratemaking request (in basis points)	100
Zoning petitions to be approved	2
Project costs that qualify for the construction work in progress incentive	308
LG And E And KU Energy LLC [Member] | Green River Plant [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	700
Expected capital cost of an expansion project	700
LG And E And KU Energy LLC [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	10
Expected capital cost of an expansion project	25
Louisville Gas And Electric Co [Member] | Green River Plant [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	700
Expected capital cost of an expansion project	700
Louisville Gas And Electric Co [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	10
Expected capital cost of an expansion project	25
Kentucky Utilities Co [Member] | Green River Plant [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	700
Expected capital cost of an expansion project	700
Kentucky Utilities Co [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Completed capacity expansion (in MW)	10
Expected capital cost of an expansion project	$ 25