Income Taxes (Reconciliation of Income Tax Expense) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended			3 Months Ended				6 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2011
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%				$ 180		$ 128		$ 377		$ 409
Federal statutory tax rate				35.00%		35.00%		35.00%		35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit				14		7		17		32
Impact of lower U.K. income tax rates				(25)	[1]	(24)	[1]	(63)	[1]	(45)	[1]
U.S. income tax on foreign earnings - net of foreign tax credit				(7)	[2]	(1)	[2]	(5)	[2]	1	[2]
Federal and state tax reserve adjustments				(39)	[3]	(4)	[3]	(40)	[3]	(5)	[3]
Foreign tax reserve adjustments						(8)	[4]			(5)	[4]
Foreign income tax return adjustments				(4)				(4)
Federal income tax credits				(2)		(3)		(5)		(7)
Amortization of investment tax credit				(2)		(3)		(5)		(5)
Depreciation not normalized				(1)		(2)		(4)		(4)
State deferred tax rate change										(11)	[5]
Net operating loss carryforward adjustments						(3)	[6]			(9)	[6]
Other				(5)		1		(8)		(4)
Total increase (decrease)				(71)		(40)		(117)		(62)
Total income tax from continuing operations				109		88		260		347
United Kingdom statutory income tax rate in effect during period prior to a change								23.00%		25.00%		27.00%
United Kingdom statutory income tax rate reduction		24.00%	26.00%
United Kingdom statutory income tax rate reduction in 2014	21.00%
United Kingdom statutory income tax rate reduction in 2015	20.00%
Increase to income tax expense primarily attributable to a revision in the expected taxable amount of cash repatriation in 2013				14				14
Benefit from favorable United States Tax Court decision on deductibility of United Kingdom windfall profit tax				44				44
Expense from reversal by United States Court of Appeals for the Third Circuit on deductibility of United Kingdom windfall profit tax								39
Benefit related to the recalculation of 2010 United Kingdom earnings and profits				(19)				(19)
Interest portion of benefit from favorable United States Tax Court decision on deductibility of United Kingdom windfall profit tax				19				19
Low end of range of estimated deferred tax benefit due to United Kingdom rate change								90
High end of range of estimated deferred tax benefit due to United Kingdom rate change								100
PPL Energy Supply LLC [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%				54		10		28		180
Federal statutory tax rate				35.00%		35.00%		35.00%		35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit				9		1		3		24
Federal and state tax reserve adjustments				7	[7]			6	[7]
Federal income tax credits						(2)		(3)		(6)
State deferred tax rate change										(11)	[8]
Other				(3)				(2)		(1)
Total increase (decrease)				13		(1)		4		6
Total income tax from continuing operations				67		9		32		186
Reversal of tax benefit related to a 2008 change in accounting method				3				3
Federal tax reserves related to differences in over (under) payment interest rates applied to audit claims as a result of the U.S. Supreme Court decision related to Windfall Profits tax				4				4
PPL Electric Utilities Corp [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%				24		14		58		34
Federal statutory tax rate				35.00%		35.00%		35.00%		35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit				3		3		8		5
Federal and state tax reserve adjustments				(2)		(2)		(4)		(3)
Depreciation not normalized				(1)		(3)		(4)		(4)
Other						(1)		(1)		(1)
Total increase (decrease)						(3)		(1)		(3)
Total income tax from continuing operations				24		11		57		31
LG And E And KU Energy LLC [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%				35		25		89		50
Federal statutory tax rate				35.00%		35.00%		35.00%		35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit				3				8		2
Net operating loss carryforward adjustments						(3)	[9]			(9)	[9]
Other				(1)		(2)		(3)		(2)
Total increase (decrease)				2		(5)		5		(9)
Total income tax from continuing operations				37		20		94		41
Louisville Gas And Electric Co [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%				16		14		40		28
Federal statutory tax rate				35.00%		35.00%		35.00%		35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit				1		1		4		3
Other						(1)		(2)		(2)
Total increase (decrease)				1				2		1
Total income tax from continuing operations				17		14		42		29
Kentucky Utilities Co [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%				25		17		61		38
Federal statutory tax rate				35.00%		35.00%		35.00%		35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit				2		2		6		4
Other				(1)		(1)		(2)		(2)
Total increase (decrease)				1		1		4		2
Total income tax from continuing operations				$ 26		$ 18		$ 65		$ 40

[1] The U.K. Finance Act 2012, enacted in July 2012, reduced the U.K. statutory income tax rate from 25% to 24% retroactive to April 1, 2012 and from 24% to 23% effective April 1, 2013. The U.K. Finance Act 2011, enacted in July 2011, reduced the U.K. statutory income tax rate from 27% to 26% retroactive to April 1, 2011 and from 26% to 25% effective April 1, 2012.

[2] During the three and six months ended June 30, 2013, PPL recorded a $14 million increase to income tax expense primarily attributable to a revision in the expected taxable amount of cash repatriation in 2013 and recorded a tax benefit of $19 million associated with a ruling obtained from the IRS impacting the recalculation of 2010 U.K. earnings and profits that will be reflected on an amended 2010 U.S. tax return.

[3] In 1997, the U.K. imposed a Windfall Profits Tax (WPT) on privatized utilities, including WPD. PPL filed its tax returns for years subsequent to its 1997 and 1998 claims for refund on the basis that the U.K. WPT was creditable. In September 2010, the U.S. Tax Court (Tax Court) ruled in PPL's favor in a dispute with the IRS, concluding that the U.K. WPT is a creditable tax for U.S. tax purposes. In January 2011, the IRS appealed the Tax Court's decision to the U.S. Court of Appeals for the Third Circuit (Third Circuit). In December 2011, the Third Circuit issued its opinion reversing the Tax Court's decision, holding that the U.K. WPT is not a creditable tax. As a result of the Third Circuit’s adverse determination, PPL recorded a $39 million expense in the fourth quarter of 2011. In June 2012, the U.S. Court of Appeals for the Fifth Circuit issued a contrary opinion in an identical case involving another company. In July 2012, PPL filed a petition for a writ of certiorari seeking U.S. Supreme Court review of the Third Circuit's opinion. The Supreme Court granted PPL's petition and oral argument was held in February 2013. On May 20, 2013, the Supreme Court reversed the Third Circuit’s opinion and ruled that the WPT is a creditable tax. As a result of the Supreme Court ruling, PPL recorded a tax benefit of $44 million during the three and six months ended June 30, 2013, of which $19 million relates to interest.

[4] During the three and six months ended June 30, 2012, PPL recorded a tax benefit following resolution of a U.K. tax issue related to the tax deductibility of interest expense.

[5] During the six months ended June 30, 2012, PPL recorded adjustments related to state deferred tax liabilities.

[6] During the three and six months ended June 30, 2012, PPL recorded adjustments to deferred taxes related to net operating loss carryforwards of LKE based on income tax return adjustments.

[7] During the three and six months ended June 30, 2013, PPL Energy Supply reversed a $3 million tax benefit related to a 2008 change in method of accounting for certain expenditures for tax purposes and recorded $4 million in federal tax reserves related to differences in over (under) payment interest rates applied to audit claims as a result of the U.S. Supreme Court decision related to Windfall Profits Tax.

[8] During the six months ended June 30, 2012, PPL Energy Supply recorded adjustments related to state deferred tax liabilities.

[9] During the three and six months ended June 30, 2012, LKE recorded adjustments to deferred taxes related to net operating loss carryforwards based on income tax return adjustments.