Goodwill and Other Intangible Assets (Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	$ 4,225	[1]	$ 4,158	[1]
Allocation to discontinued operations	(82)	[2]	0
Effect of foreign currency exchange rates	(138)		67
Balance at end of period	4,005	[1]	4,225	[1]
Kentucky Regulated [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period					662	[1]
Balance at end of period	662	[1]	662	[1]	662	[1]
United Kingdom Regulated [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	3,143	[1]	3,076	[1]
Effect of foreign currency exchange rates	(138)		67
Balance at end of period	3,005	[1]	3,143	[1]
Supply [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	420	[1]	420	[1]
Allocation to discontinued operations	(82)	[2]	0
Balance at end of period	338	[1]	420	[1]
PPL Energy Supply LLC [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at end of period	72		86
LG And E And KU Energy LLC [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at end of period	996		996
Louisville Gas And Electric Co [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at end of period	389		389
Kentucky Utilities Co [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at end of period	$ 607		$ 607

[1] There were no accumulated impairment losses related to goodwill.

[2] Represents goodwill allocated to the Montana hydroelectric generating facilities that were sold in November 2014. See Note 8 for additionalinformation.