Acquisitions, Development and Divestures (Details) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended		1 Months Ended	9 Months Ended	3 Months Ended				9 Months Ended					3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended	3 Months Ended		9 Months Ended			1 Months Ended	9 Months Ended	3 Months Ended				9 Months Ended					3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended				9 Months Ended			9 Months Ended				9 Months Ended				9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Green River Plant [Member] MW	Sep. 30, 2014 Solar Generation Facility [Member] MW	Sep. 30, 2014 Rainbow Hydroelectric Plant Expansion [Member]	Jul. 31, 2014 Holtwood Hydroelectric Plant Expansion [Member]	Sep. 30, 2014 PPL Energy Supply Spinoff [Member]	Sep. 30, 2014 Montana Hydroelectric Generating Facilities [Member] Integer		Sep. 30, 2013 Montana Hydroelectric Generating Facilities [Member]		Sep. 30, 2014 Montana Hydroelectric Generating Facilities [Member] MW Integer		Sep. 30, 2013 Montana Hydroelectric Generating Facilities [Member]		Dec. 31, 2013 Montana Hydroelectric Generating Facilities [Member]	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member] Integer	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member]	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member] Minimum [Member]	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member] Maximum [Member]	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member] Other Operation And Maintenance [Member]	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member] Other Income (Expense) Net [Member]	Sep. 30, 2014 Spinoff [Member] PPL Energy Supply Spinoff [Member] Other Income (Expense) Net [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member]	Sep. 30, 2013 PPL Energy Supply LLC [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member]	Sep. 30, 2013 PPL Energy Supply LLC [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member] Rainbow Hydroelectric Plant Expansion [Member]	Jul. 31, 2014 PPL Energy Supply LLC [Member] Holtwood Hydroelectric Plant Expansion [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member] PPL Energy Supply Spinoff [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member] Montana Hydroelectric Generating Facilities [Member] Integer		Sep. 30, 2013 PPL Energy Supply LLC [Member] Montana Hydroelectric Generating Facilities [Member]		Sep. 30, 2014 PPL Energy Supply LLC [Member] Montana Hydroelectric Generating Facilities [Member] MW Integer		Sep. 30, 2013 PPL Energy Supply LLC [Member] Montana Hydroelectric Generating Facilities [Member]		Dec. 31, 2013 PPL Energy Supply LLC [Member] Montana Hydroelectric Generating Facilities [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member] Spinoff [Member] PPL Energy Supply Spinoff [Member] Integer	Sep. 30, 2014 PPL Energy Supply LLC [Member] Spinoff [Member] PPL Energy Supply Spinoff [Member] Minimum [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member] Spinoff [Member] PPL Energy Supply Spinoff [Member] Maximum [Member]	Sep. 30, 2014 PPL Energy Supply LLC [Member] Spinoff [Member] PPL Energy Supply Spinoff [Member] Other Operation And Maintenance [Member]	Sep. 30, 2014 PPL Electric Utilities Corp [Member]	Sep. 30, 2013 PPL Electric Utilities Corp [Member]	Sep. 30, 2014 PPL Electric Utilities Corp [Member] Spinoff [Member] PPL Energy Supply Spinoff [Member] Integer	Sep. 30, 2014 PPL Electric Utilities Corp [Member] Spinoff [Member] PPL Energy Supply Spinoff [Member] Other Operation And Maintenance [Member]	Sep. 30, 2014 LG And E And KU Energy LLC [Member]	Sep. 30, 2013 LG And E And KU Energy LLC [Member]	Sep. 30, 2014 LG And E And KU Energy LLC [Member]	Sep. 30, 2013 LG And E And KU Energy LLC [Member]	Sep. 30, 2014 LG And E And KU Energy LLC [Member] Green River Plant [Member] MW	Sep. 30, 2014 LG And E And KU Energy LLC [Member] Solar Generation Facility [Member] MW	Sep. 30, 2014 Louisville Gas And Electric Co [Member]	Sep. 30, 2013 Louisville Gas And Electric Co [Member]	Sep. 30, 2014 Louisville Gas And Electric Co [Member] Green River Plant [Member] MW	Sep. 30, 2014 Louisville Gas And Electric Co [Member] Solar Generation Facility [Member] MW	Sep. 30, 2014 Kentucky Utilities Co [Member]	Sep. 30, 2013 Kentucky Utilities Co [Member]	Sep. 30, 2014 Kentucky Utilities Co [Member] Green River Plant [Member] MW	Sep. 30, 2014 Kentucky Utilities Co [Member] Solar Generation Facility [Member] MW
Divestitures - Anticipated Spinoff of PPL Energy Supply (Numeric) [Abstract]
Seperation benefits																							$ 30,000,000																						$ 12,000,000				$ 1,000,000
Number of employees impacted																			265																							100						10
Additional seperation costs to be recognized at the spinoff closing date																					30,000,000	40,000,000																					30,000,000	40,000,000
Deferred income tax recorded as result of agreement to adjust valuation allowances			266,000,000	301,000,000															3,000,000	49,000,000								(150,000,000)	112,000,000																	65,000,000	103,000,000					251,000,000	99,000,000			31,000,000	22,000,000			129,000,000	73,000,000
Spinoff transaction costs	2,000,000		18,000,000																					5,000,000	21,000,000
Spinoff anticipated transaction costs in future periods																					60,000,000	70,000,000
Divestitures - Anticipated Spinoff of PPL Energy Supply (Numeric) [Abstract]
Spinoff agreement execution date									Jun. 09, 2014																							Jun. 09, 2014
Certain details of spinoff transaction									PPL and PPL Energy Supply executed definitive agreements with affiliates of Riverstone to combine their competitive power generation businesses into a new, stand-alone, publicly traded, independent power producer named Talen Energy. Under the terms of the agreements, at closing, PPL will spin off PPL Energy Supply to PPL shareowners and simultaneously combine that business with RJS Power.																							PPL and PPL Energy Supply executed definitive agreements with affiliates of Riverstone to combine their competitive power generation businesses into a new, stand-alone, publicly traded, independent power producer named Talen Energy. Under the terms of the agreements, at closing, PPL will spin off PPL Energy Supply to PPL shareowners and simultaneously combine that business with RJS Power.
Initial percent ownership in new company, Talen Energy, by PPL shareowners									65.00%																							65.00%
Initial percent ownership in new company, Talen Energy, by Riverstone Holdings, LLC									35.00%																							35.00%
Minimum capacity of revolving credit facility for Talen required at closing under agreement terms									1,000,000,000																							1,000,000,000
Spinoff expected completion date									Expected to close in first or second quarter of 2015																							Expected to close in first or second quarter of 2015
Divestitures - Montana Hydro Sale Agreement (Numeric) [Abstract]
Capacity of facilities to be sold (in MW)														633																							633
Agreed upon sales price for disposal of hydroelectric facilities owned by PPL Montana														900,000,000																							900,000,000
Expected net cash proceeds from disposal of hydroelectric facilities owned by PPL Montana														880,000,000																							880,000,000
Number of hydroelectric facilities owned by PPL Montana to be sold										11				11																			11				11
Discontinued Operations (Details) [Abstract]
Operating revenues										33,000,000		31,000,000		103,000,000		110,000,000																	33,000,000		31,000,000		103,000,000		110,000,000
Operating expenses										20,000,000		20,000,000		77,000,000		59,000,000																	20,000,000		20,000,000		77,000,000		59,000,000
Operating income (loss)										13,000,000		11,000,000		26,000,000		51,000,000																	13,000,000		11,000,000		26,000,000		51,000,000
Interest expense										2,000,000	[1]	2,000,000	[1]	6,000,000	[1]	8,000,000	[1]																2,000,000	[1]	2,000,000	[1]	6,000,000	[1]	8,000,000	[1]
Discontinued operations										11,000,000		9,000,000		20,000,000		43,000,000																	11,000,000		9,000,000		20,000,000		43,000,000
Income tax expense (benefit)										4,000,000		3,000,000		10,000,000		15,000,000																	4,000,000		3,000,000		10,000,000		15,000,000
Income (Loss) from Discontinued Operations	7,000,000	7,000,000	10,000,000	30,000,000						7,000,000		6,000,000		10,000,000		28,000,000										7,000,000	6,000,000	10,000,000	28,000,000				7,000,000		6,000,000		10,000,000		28,000,000											0	0	0	1,000,000
Property, plant and equipment included in assets of discontinued operations										544,000,000				544,000,000				614,000,000															544,000,000				544,000,000				614,000,000
Goodwill included in assets of discontinued operations										82,000,000				82,000,000																			14,000,000				14,000,000
Development Projects [Abstract]
Planned capacity expansion (in MW)						10																																																	10				10				10
Completed capacity expansion (in MW)					700																																																	700				700				700
Expected capital cost of an expansion project					700,000,000	36,000,000																																																700,000,000	36,000,000			700,000,000	36,000,000			700,000,000	36,000,000
Treasury grants approved, accepted and to be received in lieu of tax credits							56,000,000	108,000,000																						56,000,000	108,000,000
Cumulative deferred investments tax credits to be recaptured							$ 60,000,000	$ 117,000,000																						$ 60,000,000	$ 117,000,000

[1] Represents allocated interest expense based upon debt attributable to the generation facilities being sold.