Income Taxes (Reconciliation of Income Tax Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	$ 320	$ 153
Federal statutory tax rate	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	25	3
State valuation allowance adjustments	3	0
Impact of lower U.K. income tax rates	(62)	(44)
U.S. income tax on foreign earnings - net of foreign tax credit	(1)	11
Intercompany interest on U.K. financing entities	(8)	(2)
Other	(9)	(7)
Total increase (decrease)	(52)	(39)
Total income tax from continuing operations	268	114
Subsequent Event [Member] | Minimum [Member]
Income Tax Other Numeric [Abstract]
Expected refund for open audits for the years 1998-2011, subject to a final determination of interest on the refund			(20)
Subsequent Event [Member] | Maximum [Member]
Income Tax Other Numeric [Abstract]
Expected refund for open audits for the years 1998-2011, subject to a final determination of interest on the refund			(30)
PPL Electric Utilities Corp [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	51	48
Federal statutory tax rate	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	10	8
Other	(2)	(3)
Total increase (decrease)	8	5
Total income tax from continuing operations	59	53
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	64
Federal statutory tax rate	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	7	7
State valuation allowance adjustments	3	0
Other	(2)	(2)
Total increase (decrease)	8	5
Total income tax from continuing operations	76	69
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%	30	29
Federal statutory tax rate	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	3	3
Other	0	(2)
Total increase (decrease)	3	1
Total income tax from continuing operations	33	30
Kentucky Utilities Co [Member]
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) Before Income Taxes at statutory tax rate - 35%	44	43
Federal statutory tax rate	35.00%	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	4	4
Other	(1)	(1)
Total increase (decrease)	3	3
Total income tax from continuing operations	$ 47	$ 46