Income Taxes (Reconciliation of Income Tax Expense) (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	$ 189		$ 214		$ 571		$ 547
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	$ 15		$ 13		$ 44		$ 28
Valuation allowance adjustments	0		3	[1]	8		49	[1]
Impact of lower U.K. income tax rates	(40)		(48)		(138)		(124)
U.S. income tax on foreign earnings - net of foreign tax credit	0		26	[2]	(1)		47	[2]
Federal and state tax reserve adjustments	(9)	[3]	0		(21)	[3]	0
Amortization of investment tax credit	(1)		1		(3)		(3)
Depreciation not normalized	(1)		(3)		(4)		(7)
Intercompany interest on U.K. financing entities	(4)		0		(15)		(4)
Foreign income tax return adjustments	0		0		(4)		0
Other	(5)		(5)		(5)		1
Total increase (decrease)	(45)		(13)		(139)		(13)
Total income tax from continuing operations	144		201		432		534
Benefit related to planned amendment of prior period tax return	9				9
Income Tax Other Numeric [Abstract]
Refund for open audits for the years 1998-2011, subject to a final determination of interest on the refund	24
Refund reflected in continuing operations for open audits for the years 1998-2011, subject to a final determination of interest on the refund	12
PPL Electric Utilities Corp [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	$ 32		$ 33		$ 112		$ 110
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	$ 7		$ 5		$ 21		$ 17
Depreciation not normalized	(1)		(2)		(3)		(5)
Other	(3)		1		0		(1)
Total increase (decrease)	3		4		18		11
Total income tax from continuing operations	35		37		130		121
LG And E And KU Energy LLC [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	$ 68		$ 51		$ 172		$ 153
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	$ 7		$ 6		$ 18		$ 16
Valuation allowance adjustments	0		0		8	[4]	0
Amortization of investment tax credit	(1)		(1)		(2)		(3)
Other	(1)		(1)		(2)		(1)
Total increase (decrease)	5		4		22		12
Total income tax from continuing operations	73		55		194		165
Louisville Gas And Electric Co [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	$ 33		$ 26		$ 83		$ 74
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	$ 4		$ 3		$ 9		$ 8
Other	(1)		(2)		(1)		(4)
Total increase (decrease)	3		1		8		4
Total income tax from continuing operations	36		27		91		78
Kentucky Utilities Co [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	$ 41		$ 32		$ 106		$ 98
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	$ 4		$ 3		$ 11		$ 10
Other	(1)		(1)		(2)		(2)
Total increase (decrease)	3		2		9		8
Total income tax from continuing operations	$ 44		$ 34		$ 115		$ 106

[1] As a result of the spinoff announceme nt, PPL recorded deferred income tax expense during the three and nine months ended September 30, 2014 to adjust valuation allowances on deferred tax assets primarily for state net operating loss carryforwards that were previously supported by the future earnings of PPL Energy Supply. See Note 8 for additional information on the spinoff .

[2] During the three and nine months ended September 30, 201 5 , PPL recorded lower income tax expense due to a dec rease in taxable dividends .

[3] During the three and nine months ended September 30, 2015, PPL recorded a $9 million tax benefit related to a planned amendment of a prior period tax return. During the nine months ended September 30 , 2015, PPL recorded a $12 million tax benefit to adjust the settled refund amount approved by the Joint Committee of Taxation for the open audit years 1998-2011 .

[4] Represents a valuation allowance against tax credits expiring in 2016 and 2017 that are more likely than not to expire before being utilized.