Acquisitions, Development and Divestures (Details) $ in Millions	3 Months Ended				6 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Integer	Mar. 31, 2015 Integer	Sep. 30, 2014 USD ($)		Jun. 30, 2015 USD ($) Integer shares		Sep. 30, 2015 USD ($) Integer MW		Sep. 30, 2014 USD ($)		Dec. 31, 2014 USD ($)
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Deferred income tax recorded as result of agreement to adjust valuation allowances							$ 359		$ 416
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Results of Discontinued Operations (Details) [Abstract]
Income (Loss) from Discontinued Operations (net of income taxes)	$ (3)		$ 87				(915)		13
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Total Current Assets	0						0				$ 2,600
Total Noncurrent Assets	0						0				8,317
Total Current Liabilities	0						0				2,775
Accrued pension obligations	244						244
Total Nonurrent Liabilities	0						$ 0				3,963
Solar Generation Facility [Member]
Development Projects [Abstract]
Planned capacity expansion (in MW) | MW							10
Expected capital cost of an expansion project	36						$ 36
Spinoff [Member] | PPL Energy Supply Spinoff [Member]
Discontinued Operations - Spinoff of PPL Energy Supply - Cost of Spinoff (Numberic) [Abstract]
Amount of accrued libality for seperation benefits	11						11				21
Spinoff transaction costs			5				44		21
Spinoff [Member] | PPL Energy Supply Spinoff [Member] | Other Operation And Maintenance [Member]
Discontinued Operations - Spinoff of PPL Energy Supply - Cost of Spinoff (Numberic) [Abstract]
Spinoff transaction costs							13
Spinoff [Member] | PPL Energy Supply Spinoff [Member] | Discontinued Operations [Member]
Discontinued Operations - Spinoff of PPL Energy Supply - Cost of Spinoff (Numberic) [Abstract]
Seperation benefits							24
Spinoff transaction costs							$ 31
PPL Energy Supply Spinoff [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Spinoff agreement execution date					Jun. 09, 2014
Date of record					May 20, 2015
Effective date of spinoff					Jun. 01, 2015
Certain details of spinoff transaction							In June 2014, PPL and PPL Energy Supply executed definitive agreements with affiliates of Riverstone to spin off PPL Energy Supply and immediately combine it with Riverstone’s competitive power generation businesses to form a new, stand-alone, publicly traded company named Talen Energy. The transaction was subject to customary closing conditions, including receipt of regulatory approvals from the NRC, FERC, DOJ and PUC, all of which were received by mid-April 2015. On April 29, 2015, PPL’s Board of Directors declared the June 1, 2015 distribution to PPL’s shareowners of record on May 20, 2015 of a newly formed entity, Holdco, which at closing owned all of the membership interests of PPL Energy Supply and all of the common stock of Talen Energy.
Number of shares of Talen common stock for one share of PPL common stock | shares					0.1249
Initial percent ownership in new company, Talen Energy, by PPL shareowners					65.00%
Initial percent ownership in new company, Talen Energy, by Riverstone Holdings, LLC					35.00%
Number of approaches | Integer					3
Weighted fair value					$ 3,224
Control premium					25.00%
Number of market approaches | Integer					2
Review period used in determing the control premium (in years)					5 years
Mimimum transaction value reviewed in determining the control premium					$ 1,000
Carrying value of the Supply segment					$ 4,100
Gain (loss) on interest rate swaps recognized in discontinued operations on the statement of income							$ 72
Gain (loss), after-tax, on interest rate swaps recognized in discontinued operations on the statement of income							42
Deferred income tax recorded as result of agreement to adjust valuation allowances			3						49
Maximum period for Transition Service Agreement (in years)					2 years
Amount for services billed to spinoff	11						14
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Results of Discontinued Operations (Details) [Abstract]
Operating revenues	0		1,623				1,427		1,741
Operating expenses	0		1,429				1,328		1,593
Other Income (Expense) - net	0		8				(22)		6
Interest Expense	0		47	[1]			150	[1]	145	[1]
Income (loss) before income taxes	0		155				(73)		9
Income tax expense (benefit)	3		68				(37)		(4)
Loss on spinoff	0		0				(879)		0
Income (Loss) from Discontinued Operations (net of income taxes)	(3)		87				(915)		13
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Cash and cash equivalents					$ 371	[2]					352
Restricted cash and cash equivalents					156						176
Accounts receivable and unbilled revenues					325						504
Fuels, materials and supplies					415						455
Price risk management assets					784						1,079
Other current assets					65						34
Total Current Assets					2,116						2,600
Investments					999						980
Property Plant and Equipment, net					6,384						6,428
Goodwill					338						338
Other intangibles					260						257
Price risk management assets					244						239
Other noncurrent assets					78						75
Total Noncurrent Assets					8,303						8,317
Total assets					10,419						10,917
Short-term debt and long-term debt due within one year					885						1,165
Accounts payable					252						361
Price risk management liabilities					763						1,024
Other current liabilities					229						225
Total Current Liabilities					2,129						2,775
Long-term debt (excluding current portion)					1,932						1,683
Deferred income taxes					1,259						1,223
Price risk management liabilities					206						193
Accrued pension obligations					244						299
Asset retirement obligations					443						415
Other deferred credits and noncurrent liabilities					103						150
Total Nonurrent Liabilities					4,187						3,963
Total liabilities					6,316						$ 6,738
Adjustment for loss on spinoff	$ 0		$ 0				$ 879		0
Net assets distributed					$ 3,224
PPL Energy Supply Spinoff [Member] | Minimum [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Control premium					5.00%
PPL Energy Supply Spinoff [Member] | Maximum [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Control premium					42.00%
PPL Energy Supply Spinoff [Member] | Talen Energy Market Value [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Weighting					50.00%
Weighted fair value					$ 1,400
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed					$ 1,400
PPL Energy Supply Spinoff [Member] | Income Discounted Cash Flow [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Weighting					30.00%
Weighted fair value					$ 1,100
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed					$ 1,100
PPL Energy Supply Spinoff [Member] | Alternative Market Comparable Company [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Weighting					20.00%
Weighted fair value					$ 700
Discontinued Operations - Spinoff of PPL Energy Supply - Summarized Assets and Liabilities of Discontinued Operations (Details) [Abstract]
Net assets distributed					$ 700
Montana Hydroelectric Generating Facilities [Member]
Divestitures - Montana Hydro Sale Agreement (Numeric) [Abstract]
Capacity of facilities sold (in MW) | MW							633
Agreed upon sales price for disposal of hydroelectric facilities owned by PPL Montana							$ 900
Number of hydroelectric facilities owned by PPL Montana sold | Integer	11						11
LGE [Member]
Development Projects [Abstract]
Generating units retired at the Cane Run plant | Integer		1			2
LGE [Member] | Cane Run Unit 7 [Member]
Development Projects [Abstract]
Costs associated with the retirement of generating units	$ 11						$ 11
KU [Member]
Development Projects [Abstract]
Generating units retired at the Green River plant | Integer							2
Costs associated with the retirement of generating units	6						$ 6
PPL Electric Utilities Corp [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Deferred income tax recorded as result of agreement to adjust valuation allowances							127		65
LG And E And KU Energy LLC [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Deferred income tax recorded as result of agreement to adjust valuation allowances							$ 199		251
LG And E And KU Energy LLC [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Planned capacity expansion (in MW) | MW							10
Expected capital cost of an expansion project	36						$ 36
LG And E And KU Energy LLC [Member] | LGE [Member]
Development Projects [Abstract]
Generating units retired at the Cane Run plant | Integer		1			2
LG And E And KU Energy LLC [Member] | LGE [Member] | Cane Run Unit 7 [Member]
Development Projects [Abstract]
Costs associated with the retirement of generating units	11						$ 11
LG And E And KU Energy LLC [Member] | KU [Member]
Development Projects [Abstract]
Generating units retired at the Green River plant | Integer							2
Costs associated with the retirement of generating units	6						$ 6
Louisville Gas And Electric Co [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Deferred income tax recorded as result of agreement to adjust valuation allowances							93		31
Development Projects [Abstract]
Generating units retired at the Cane Run plant | Integer		1			2
Louisville Gas And Electric Co [Member] | Cane Run Unit 7 [Member]
Development Projects [Abstract]
Costs associated with the retirement of generating units	11						$ 11
Louisville Gas And Electric Co [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Planned capacity expansion (in MW) | MW							10
Expected capital cost of an expansion project	36						$ 36
Kentucky Utilities Co [Member]
Discontinued Operations - Spinoff of PPL Energy Supply (Numeric) [Abstract]
Deferred income tax recorded as result of agreement to adjust valuation allowances							$ 132		$ 129
Development Projects [Abstract]
Generating units retired at the Green River plant | Integer							2
Costs associated with the retirement of generating units	6						$ 6
Kentucky Utilities Co [Member] | Solar Generation Facility [Member]
Development Projects [Abstract]
Planned capacity expansion (in MW) | MW							10
Expected capital cost of an expansion project	$ 36						$ 36

[1] Includes interest associated with the Supply Segment with no additional allocation as the Supply segment was sufficiently capitalized.

[2] The distribution of PPL Energy Supply ’s cash and cash equivalents at June 1, 2015 is included in "Net cash provided by (used in) financing activities - discontinu ed operations" on the Statement of Cash Flows for the nine months ended September 30, 2015 .