CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended						2 Months Ended	12 Months Ended		10 Months Ended	2 Months Ended	12 Months Ended		10 Months Ended	2 Months Ended	12 Months Ended		10 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 PPL Energy Supply LLC [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member]	Dec. 31, 2010 PPL Energy Supply LLC [Member]	Dec. 31, 2010 LG And E And KU Energy LLC [Member] Successor [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Successor [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Successor [Member]	Oct. 31, 2010 LG And E And KU Energy LLC [Member] Predecessor [Member]	Dec. 31, 2010 Louisville Gas And Electric Co [Member] Successor [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Successor [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Successor [Member]	Oct. 31, 2010 Louisville Gas And Electric Co [Member] Predecessor [Member]	Dec. 31, 2010 Kentucky Utilities Co [Member] Successor [Member]	Dec. 31, 2012 Kentucky Utilities Co [Member] Successor [Member]	Dec. 31, 2011 Kentucky Utilities Co [Member] Successor [Member]	Oct. 31, 2010 Kentucky Utilities Co [Member] Predecessor [Member]
Net income	$ 1,531	$ 1,512	$ 959	$ 475	$ 769	$ 862	$ 47	$ 219	$ 265	$ 190	$ 19	$ 123	$ 124	$ 109	$ 35	$ 137	$ 178	$ 140
Amounts arising during the period - gains (losses), net of tax (expense) benefit:
Foreign currency translation adjustments, net of tax	94	(48)	(59)			(59)
Available-for-sale securities, net of tax	29	9	29	29	9	29
Qualifying derivatives, net of tax	39	202	219	68	267	305				10				10
Equity investees' other comprehensive income (loss), net of tax	2							1		(2)						1		(2)
Defined benefit plans:
Prior service costs, net of tax	1	(3)	17	1	(2)	12			(2)
Net actuarial gain (loss), net of tax	(965)	(152)	(80)	(82)	(22)	(63)	6	(21)		(20)
Transition obligation, net of tax			8			6
Reclassifications to net income - (gains) losses, net of tax expense (benefit):
Available-for-sale securities, net of tax	(7)	(7)	(5)	(7)	(7)	(5)
Qualifying derivatives, net of tax	(434)	(370)	(126)	(463)	(353)	(145)
Equity investee's other comprehensive (income) loss, net of tax		3			3
Defined benefit plans:
Prior service costs, net of tax	10	10	12	5	4	9				1
Net actuarial loss, net of tax	79	47	41	10	4	39		1		1
Transition obligation, net of tax			2			1
Total other comprehensive income (loss)	(1,152)	(309)	58	(439)	(97)	129	6	(19)	(2)	(10)				10		1		(2)
Comprehensive income (loss)	379	1,203	1,017	36	672	991					19	123	124	119	35	138	178	138
Comprehensive income attributable to noncontrolling interests	5	17	21	1	1	1
Comprehensive income (loss) attributable to Shareowners	$ 374	$ 1,186	$ 996	$ 35	$ 671	$ 990	$ 53	$ 200	$ 263	$ 180