Goodwill and Other Intangible Assets (Other Intangibles) (Details) (USD $) In Millions, unless otherwise specified																12 Months Ended										12 Months Ended																12 Months Ended									12 Months Ended																					12 Months Ended								2 Months Ended	12 Months Ended		2 Months Ended	12 Months Ended		2 Months Ended	12 Months Ended												12 Months Ended								10 Months Ended	12 Months Ended		10 Months Ended	12 Months Ended		10 Months Ended	12 Months Ended												12 Months Ended								2 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Land And Transmission Rights [Member]	Dec. 31, 2011 Land And Transmission Rights [Member]	Dec. 31, 2012 Easements [Member]	Dec. 31, 2011 Easements [Member]		Dec. 31, 2012 Contracts [Member]		Dec. 31, 2011 Contracts [Member]		Dec. 31, 2012 Coal Contracts [Member]	Dec. 31, 2011 Coal Contracts [Member]	Dec. 31, 2012 Land And Transmission Rights [Member]	Dec. 31, 2011 Land And Transmission Rights [Member]	Dec. 31, 2012 Emission Allowances And Renewable Energy Credits [Member]		Dec. 31, 2011 Emission Allowances And Renewable Energy Credits [Member]		Dec. 31, 2010 Emission Allowances And Renewable Energy Credits [Member]	Dec. 31, 2011 Emission Allowances [Member]	Dec. 31, 2012 Licenses And Other [Member]		Dec. 31, 2011 Licenses And Other [Member]		Dec. 31, 2012 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2011 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2010 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2012 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2011 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2010 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2012 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2011 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2010 Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Contracts [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Contracts [Member]		Dec. 31, 2012 PPL Energy Supply LLC [Member] Land And Transmission Rights [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Land And Transmission Rights [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Emission Allowances And Renewable Energy Credits [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Emission Allowances And Renewable Energy Credits [Member]		Dec. 31, 2010 PPL Energy Supply LLC [Member] Emission Allowances And Renewable Energy Credits [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Licenses And Other [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Licenses And Other [Member]		Dec. 31, 2012 PPL Energy Supply LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2010 PPL Energy Supply LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2012 PPL Electric Utilities Corp [Member]	Dec. 31, 2011 PPL Electric Utilities Corp [Member]	Dec. 31, 2012 PPL Electric Utilities Corp [Member] Land And Transmission Rights [Member]	Dec. 31, 2011 PPL Electric Utilities Corp [Member] Land And Transmission Rights [Member]	Dec. 31, 2012 PPL Electric Utilities Corp [Member] Land And Transmission Rights [Member]	Dec. 31, 2011 PPL Electric Utilities Corp [Member] Land And Transmission Rights [Member]	Dec. 31, 2012 PPL Electric Utilities Corp [Member] Licenses And Other [Member]	Dec. 31, 2011 PPL Electric Utilities Corp [Member] Licenses And Other [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Coal Contracts [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Coal Contracts [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Land And Transmission Rights [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Land And Transmission Rights [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Emission Allowances [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Emission Allowances [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Ohio Valley Electric Corporation Power Purchase Agreement [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Ohio Valley Electric Corporation Power Purchase Agreement [Member]		Dec. 31, 2010 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2010 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2010 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Coal Contracts [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Coal Contracts [Member]		Dec. 31, 2012 Louisville Gas And Electric Co [Member] Land And Transmission Rights [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Land And Transmission Rights [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Emission Allowances [Member]		Dec. 31, 2012 Louisville Gas And Electric Co [Member] Emission Allowances [Member]		Dec. 31, 2012 Louisville Gas And Electric Co [Member] Ohio Valley Electric Corporation Power Purchase Agreement [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Ohio Valley Electric Corporation Power Purchase Agreement [Member]		Oct. 31, 2010 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits [Member]	Oct. 31, 2010 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Oct. 31, 2010 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With No Regulatory Offset [Member]	Dec. 31, 2012 Kentucky Utilities Co [Member]	Dec. 31, 2011 Kentucky Utilities Co [Member]	Dec. 31, 2012 Kentucky Utilities Co [Member] Coal Contracts [Member]		Dec. 31, 2011 Kentucky Utilities Co [Member] Coal Contracts [Member]		Dec. 31, 2012 Kentucky Utilities Co [Member] Land And Transmission Rights [Member]		Dec. 31, 2011 Kentucky Utilities Co [Member] Land And Transmission Rights [Member]		Dec. 31, 2011 Kentucky Utilities Co [Member] Emission Allowances [Member]		Dec. 31, 2012 Kentucky Utilities Co [Member] Emission Allowances [Member]		Dec. 31, 2012 Kentucky Utilities Co [Member] Ohio Valley Electric Corporation Power Purchase Agreement [Member]		Dec. 31, 2011 Kentucky Utilities Co [Member] Ohio Valley Electric Corporation Power Purchase Agreement [Member]		Dec. 31, 2010 Kentucky Utilities Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2012 Kentucky Utilities Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]	Dec. 31, 2011 Kentucky Utilities Co [Member] Other Intangibles Excluding Emission Allowances And Or Renewable Energy Credits With Regulatory Offset [Member]
Subject to amortization: [Abstract]
Gross carrying amount	$ 996	$ 1,159						$ 408	[1],[2]	$ 611	[1],[2],[3]	$ 269	$ 269	$ 284	$ 263	$ 17	[4],[5]	$ 20	[4],[5],[6]			$ 287	[7]	$ 265	[7]										$ 307	$ 490		$ 203	[1]	$ 17	$ 17	$ 13	[8]	$ 15	[8],[9]		$ 277	[7]	$ 255	[7]				$ 253	$ 236			$ 249	$ 232	$ 4	$ 4	$ 417	$ 414	$ 269	[10]	$ 269	[10]	$ 18	[11]	$ 14	[11]	$ 5	[12]	$ 4	[12]	$ 126	[13]	$ 126	[13]										$ 220	$ 219	$ 124	[10]	$ 124	[10]	$ 8	[14]	$ 6	[14]	$ 2	[15]	$ 1	[15]	$ 87	[13]	$ 87	[13]										$ 197	$ 195	$ 145	[10]	$ 145	[10]	$ 10	[16]	$ 8	[16]	$ 3	[17]	$ 3	[17]	$ 39	[13]	$ 39	[13]
Finite-Lived Intangible Assets, Accumulated Amortization	302	300						150	[3]	155	[3]			113	110							39	[7]	35	[7]										48	96		53	[1]	13	13						35	[7]	30	[7]				100	97			99	96	1	1	146	99	128	[10]	89	[10]	1	[11]	1	[11]					17		9											76	53	62	[10]	46	[10]	1	[14]	1	[14]					13		6											70	46	66	[10]	43	[10]									4		3
Impairment charges recorded during the period																		7																										7
Amortization expense																12		16		45	11					61	112	35	47	87	11	14	25	24								12		16		46					9	20	20																			11								11	47	88	11	47	87			1											5								7	23	46	7	23	45			1											6								4	24	42
Forecasted amortization in 2013																										62			52			10																			5																																	52																											25					27
Forecasted amortization in 2014																										56			46			10																			5																																	46																											23					23
Forecasted amortization in 2015																										61			51			10																			5																																	51																											24					27
Forecasted amortization in 2016																										35			27			8																			3																																	27																											14					13
Forecasted amortization in 2017																										17			9			8																			3																																	9																											6					3
Not subject to amortization due to indefinite life: [Line Items]
Gross carrying amount	238	215	18	16	220	199	[18]																																																	18	16
Gross carrying amount - other intangible assets	$ 1,234	$ 1,374																																																				$ 271	$ 252

[1] In 2012, intangible assets related to a tolling agreement were eliminated in consolidation as a result of the Ironwood Acquisition. See Note 10 for additional information.

[2] The gross carrying amount includes $269 million of coal contracts related to LKE, which represents the fair value of contracts with terms that are favorable to market recognized as a result of the 2010 acquisition of LKE by PPL. An offsetting regulatory liability was recorded related to these contracts, which is being amortized over the same period as the intangible assets, eliminating any income statement impact. See Note 6 for additional information.

[3] Gross carrying amount for 2011 includes $10 million, which represents the fair value of customer contracts with terms favorable to market recognized as a result of the 2011 acquisition of WPD Midlands. The weighted-average amortization period of these contracts was ten years at the acquisition date. See Note 10 for additional information.

[4] PPL Energy Supply emission allowances/RECs are expensed when consumed or sold. Consumption expense was $12 million, $16 million, and $45 million in 2012, 2011 and 2010. Consumption expense is expected to be insignificant in future periods.

[5] Includes emission allowances of LKE. An offsetting regulatory liability is recorded related to these emission allowances, which is being amortized as the emission allowances are consumed, eliminating any income statement impact. The carrying amounts of these emission allowances were insignificant at December 31, 2012 and 2011. Consumption related to these emission allowances was insignificant in 2012 and $11 million in 2011.

[6] During 2011, PPL recorded $7 million of impairment charges. See Note 18 for additional information.

[7] "Other" includes costs for the development of licenses, the most significant of which is the COLA. Amortization of these costs begins when the related asset is placed in service. See Note 8 for additional information on the COLA.

[8] These emission allowances/RECs are expensed when consumed or sold. Consumption expense was $12 million, $16 million, and $46 million in 2012, 2011, and 2010. Consumption expense is expected to be insignificant in future periods.

[9] During 2011, PPL Energy Supply recorded $7 million of impairment charges. See Note 18 for additional information.

[10] Gross carrying amount represents the fair value of coal contracts with terms favorable to market recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability was recorded related to these contracts, which is being amortized over the same period as the intangible assets, eliminating any income statement impact. See Note 6 for additional information.

[11] Gross carrying amount includes $14 million, which represents the fair value of land and transmission rights recognized as an intangible asset as a result of adopting PPL's accounting policies in the Successor period. Amortization expense is recovered through base rates and is expected to be insignificant for future periods.

[12] Represents the fair value of emission allowances recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability is recorded related to these emission allowances, which is being amortized as the emission allowances are consumed, eliminating any income statement impact. Consumption related to these emission allowances was insignificant in 2012 and $11 million in 2011.

[13] Gross carrying amount represents the fair value of the OVEC power purchase contract recognized as a result of the 2010 acquisition by PPL. See Note 6 for additional information.

[14] Gross carrying amount includes $6 million, which represents the fair value of land and transmission rights recognized as an intangible asset as a result of adopting PPL's accounting policies in the Successor period. Amortization expense is recovered through base rates and is expected to be insignificant for future periods.

[15] Represents the fair value of emission allowances recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability is recorded related to these emission allowances, which is being amortized as the emission allowances are consumed, eliminating any income statement impact. Consumption related to these emission allowances was insignificant in 2012 and $5 million in 2011.

[16] Gross carrying amount includes $8 million, which represents the fair value of land and transmission rights recognized as an intangible asset as a result of adopting PPL's accounting policies in the Successor period. Amortization expense is recovered through base rates and is expected to be insignificant for future periods.

[17] Represents the fair value of emission allowances recognized as a result of the 2010 acquisition by PPL. An offsetting regulatory liability is recorded related to these emission allowances, which is being amortized as the emission allowances are consumed, eliminating any income statement impact. Consumption related to these emission allowances was $6 million for 2011. KU had no consumption related to these emission allowances in 2012.

[18] Gross carrying amount for 2011 includes $88 million, which represents the fair value of easements recognized as a result of the 2011 acquisition of WPD Midlands. See Note 10 for additional information.