Derivative Instruments and Hedging Activities (Offseting Derivative Instruments and Credit Risk-Related Features) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Offsetting Assets And Liabilities [Line Items]
Gross assets	$ 1,377		$ 1,279
Derivative instruments eligible for offset - assets	1,179		973
Cash collateral received eligible for offset - assets	12		7
Net assets	186		299
Gross liabilities	1,757		1,244
Derivative instruments eligible for offset - liabilities	1,179		973
Cash collateral pledged eligible for offset - liabilities	203		24
Net liabilities	375		247
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	373
Aggregate fair value of collateral posted on these derivative instruments	155
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	265	[1],[2]
Energy Commodities [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	1,374		1,188
Derivative instruments eligible for offset - assets	1,176		912
Cash collateral received eligible for offset - assets	12		7
Net assets	186		269
Gross liabilities	1,480		1,070
Derivative instruments eligible for offset - liabilities	1,176		912
Cash collateral pledged eligible for offset - liabilities	148		1
Net liabilities	156		157
Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	3		91
Derivative instruments eligible for offset - assets	3		61
Cash collateral received eligible for offset - assets
Net assets			30
Gross liabilities	277		174
Derivative instruments eligible for offset - liabilities	3		61
Cash collateral pledged eligible for offset - liabilities	55		23
Net liabilities	219		90
PPL Energy Supply LLC [Member]
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	155
Aggregate fair value of collateral posted on these derivative instruments	134
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	68	[1],[2]
PPL Energy Supply LLC [Member] | Energy Commodities [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets	1,374		1,188
Derivative instruments eligible for offset - assets	1,176		912
Cash collateral received eligible for offset - assets	12		7
Net assets	186		269
Gross liabilities	1,480		1,070
Derivative instruments eligible for offset - liabilities	1,176		912
Cash collateral pledged eligible for offset - liabilities	148		1
Net liabilities	156		157
LG And E And KU Energy LLC [Member]
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	28
Aggregate fair value of collateral posted on these derivative instruments	21
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	8	[1]
LG And E And KU Energy LLC [Member] | Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets
Derivative instruments eligible for offset - assets
Cash collateral received eligible for offset - assets
Net assets
Gross liabilities	42		36
Derivative instruments eligible for offset - liabilities
Cash collateral pledged eligible for offset - liabilities	21		20
Net liabilities	21		16
Louisville Gas And Electric Co [Member]
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	28
Aggregate fair value of collateral posted on these derivative instruments	21
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	8	[1]
Louisville Gas And Electric Co [Member] | Treasury Derivatives [Member]
Offsetting Assets And Liabilities [Line Items]
Gross assets
Derivative instruments eligible for offset - assets
Cash collateral received eligible for offset - assets
Net assets
Gross liabilities	42		36
Derivative instruments eligible for offset - liabilities
Cash collateral pledged eligible for offset - liabilities	21		20
Net liabilities	$ 21		$ 16

[1] Includes the effect of net receivables and payables already recorded on the Balance Sheet.

[2] During the second quarter of 2014, PPL Energy Supply experienced a downgrade in its corporate credit ratings to below investment grade. Amounts related to PPL Energy Supply represent net liability positions subject to further adequate assurance features.