Goodwill and Other Intangible Assets (Goodwill) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended																			12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2012 Kentucky Regulated [Member]		Dec. 31, 2011 Kentucky Regulated [Member]		Dec. 31, 2012 United Kingdom Regulated [Member]		Dec. 31, 2011 United Kingdom Regulated [Member]		Dec. 31, 2012 Supply [Member]		Dec. 31, 2011 Supply [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member]		Dec. 31, 2012 PPL Energy Supply LLC [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] United Kingdom Regulated [Member]		Dec. 31, 2012 PPL Energy Supply LLC [Member] Supply [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Supply [Member]		Dec. 31, 2010 PPL Energy Supply LLC [Member] Supply [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member]	Dec. 31, 2012 Kentucky Utilities Co [Member]	Dec. 31, 2011 Kentucky Utilities Co [Member]
Changes in the Carrying Amount of Goodwill by Segment [Roll Forward]
Balance at beginning of period	$ 4,114		$ 1,761	[1]	$ 662	[1]	$ 662	[1]	$ 3,032	[1]	$ 679	[1]	$ 420	[1]	$ 420	[1]	$ 765	[1]	$ 86	$ 679	[2]	$ 86	[1]	$ 86	[1]	$ 86	[1]	$ 996	$ 996	$ 389	$ 389	$ 607	$ 607
Goodwill recognized during the period	(14)	[2]	2,391	[2]					(14)	[2]	2,391	[2]
Effect of foreign currency exchange rates	58		(38)						58		(38)
Derecognition																	(679)	[3]		(679)	[3]
Balance at end of period	$ 4,158		$ 4,114		$ 662	[1]	$ 662	[1]	$ 3,076	[1]	$ 3,032	[1]	$ 420	[1]	$ 420	[1]	$ 86		$ 86			$ 86	[1]	$ 86	[1]	$ 86	[1]	$ 996	$ 996	$ 389	$ 389	$ 607	$ 607

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

[2] Represents goodwill recognized as a result of the acquisition of WPD Midlands. See Note 10 for additional information.

[3] Represents the amount of goodwill derecognized as a result of PPL Energy Supply's distribution of its membership interest in PPL Global to PPL Energy Supply's parent, PPL Energy Funding. See Note 9 for additional information on the distribution. Subsequent to the distribution, PPL Energy Supply operates in a single reportable segment and reporting unit.