CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended						2 Months Ended	12 Months Ended	10 Months Ended	12 Months Ended	2 Months Ended	12 Months Ended	10 Months Ended	12 Months Ended	2 Months Ended	12 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 PPL Energy Supply [Member]	Dec. 31, 2010 PPL Energy Supply [Member]	Dec. 31, 2009 PPL Energy Supply [Member]	Dec. 31, 2010 LKE [Member] Successor [Member]	Dec. 31, 2011 LKE [Member] Successor [Member]	Oct. 31, 2010 LKE [Member] Predecessor [Member]	Dec. 31, 2009 LKE [Member] Predecessor [Member]	Dec. 31, 2010 LGE [Member] Successor [Member]	Dec. 31, 2011 LGE [Member] Successor [Member]	Oct. 31, 2010 LGE [Member] Predecessor [Member]	Dec. 31, 2009 LGE [Member] Predecessor [Member]	Dec. 31, 2010 KU [Member] Successor [Member]	Dec. 31, 2011 KU [Member] Successor [Member]	Oct. 31, 2010 KU [Member] Predecessor [Member]	Dec. 31, 2009 KU [Member] Predecessor [Member]
Tax effect of foreign currency translation adjustments arising during the period	$ (2)	$ (1)	$ 4	$ 0	$ (1)	$ 4	$ 0	$ 0	$ 0	$ 2
Tax effect of available-for-sale securities arising during the period	(6)	(31)	(50)	(6)	(31)	(50)
Tax effect of qualifying derivatives arising during the period	(139)	(148)	(356)	(164)	(207)	(330)	0	0	(7)	(2)	0	0	(7)	(2)
Tax effect of equity investees' other comprehensive income (loss) arising during the period	0	0	0	0	0	0	0	0	1	0					0	0	1	0
Tax effect of defined benefit plans - prior service costs arising during period	(1)	(14)	(1)	(2)	(8)	0	0	1	0	0
Tax effect of defined benefit plans - net actuarial gain (loss) arising during period	58	50	147	13	36	136	(3)	(1)	15	(7)
Tax effect of defined benefit plans - net transition obligation arising during period	0	(4)	0	0	(3)	0
Tax effect of available-for-sale securities reclassified to net income	5	3	3	5	3	3
Tax effect of qualifying derivatives reclassified to net income	246	84	(92)	242	99	(91)	0	0	0	0	0	0	0	0
Tax effect of equity investees' other comprehensive income (loss) reclassified to net income	0	0	0	0	0	0
Tax effect of prior service costs reclassified to net income	(5)	(7)	(8)	(3)	(5)	(6)	0	0	(1)	(2)
Tax effect of net actuarial loss reclassified to net income	(19)	(14)	(4)	(2)	(14)	(3)	0	1	(1)	(2)
Tax effect of transition obligation reclassified to net income	0	(1)	(1)	0	(1)	(1)
Tax effect of foreign currency translation adjustments allocable to discontinued operations							$ 0	$ 0	$ 0	$ (1)