Derivative Instruments and Hedging Activities (Offseting Derivative Instruments and Credit Risk-Related Features) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Offsetting Assets and Liabilities [Line Items]
Gross assets	$ 1,279		$ 2,097
Derivative instruments eligible for offset - assets	973		1,432
Net assets	299		554
Gross liabilities	1,244		1,694
Derivative instruments eligible for offset - liabilities	973		1,432
Cash collateral pledged eligible for offset - liabilities	24		39
Net liabilities	247		223
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	245
Aggregate fair value of collateral posted on these derivative instruments	41
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	214	[1]
Energy Commodities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross assets	1,188		2,068
Derivative instruments eligible for offset - assets	912		1,413
Cash collateral received eligible for offset - assets	7		111
Net assets	269		544
Gross liabilities	1,070		1,566
Derivative instruments eligible for offset - liabilities	912		1,413
Cash collateral pledged eligible for offset - liabilities	1		9
Net liabilities	157		144
Treasury Derivatives [Member]
Offsetting Assets and Liabilities [Line Items]
Gross assets	91		29
Derivative instruments eligible for offset - assets	61		19
Cash collateral received eligible for offset - assets
Net assets	30		10
Gross liabilities	174		128
Derivative instruments eligible for offset - liabilities	61		19
Cash collateral pledged eligible for offset - liabilities	23		30
Net liabilities	90		79
PPL Energy Supply LLC [Member]
Offsetting Assets and Liabilities [Line Items]
Cash collateral received eligible for offset - assets	9		112
Credit Risk-Related Contingent Features [Abstract]
Aggregate fair value of derivative instruments in a net liability position with credit risk-related contingent features	157
Aggregate fair value of collateral posted on these derivative instruments	19
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	147	[1]
PPL Energy Supply LLC [Member] | Energy Commodities [Member]
Offsetting Assets and Liabilities [Line Items]
Gross assets	1,188		2,068
Derivative instruments eligible for offset - assets	912		1,413
Cash collateral received eligible for offset - assets	7		111
Net assets	269		544
Gross liabilities	1,070		1,566
Derivative instruments eligible for offset - liabilities	912		1,413
Cash collateral pledged eligible for offset - liabilities	1		9
Net liabilities	157		144
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	26
Aggregate fair value of collateral posted on these derivative instruments	22
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	6	[1]
LG And E And KU Energy LLC [Member] | Treasury Derivatives [Member]
Offsetting Assets and Liabilities [Line Items]
Gross assets			14
Derivative instruments eligible for offset - assets
Cash collateral received eligible for offset - assets
Net assets			14
Gross liabilities	36		58
Derivative instruments eligible for offset - liabilities
Cash collateral pledged eligible for offset - liabilities	20		30
Net liabilities	16		28
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	26
Aggregate fair value of collateral posted on these derivative instruments	22
Aggregate fair value of additional collateral requirements in the event of a credit downgrade below investment grade	6	[1]
Louisville Gas And Electric Co [Member] | Treasury Derivatives [Member]
Offsetting Assets and Liabilities [Line Items]
Gross assets			7
Derivative instruments eligible for offset - assets
Cash collateral received eligible for offset - assets
Net assets			7
Gross liabilities	36		58
Derivative instruments eligible for offset - liabilities
Cash collateral pledged eligible for offset - liabilities	20		30
Net liabilities	16		28
Kentucky Utilities Co [Member] | Treasury Derivatives [Member]
Offsetting Assets and Liabilities [Line Items]
Gross assets			7
Derivative instruments eligible for offset - assets
Cash collateral received eligible for offset - assets
Net assets			7
Gross liabilities
Derivative instruments eligible for offset - liabilities
Cash collateral pledged eligible for offset - liabilities
Net liabilities

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