CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Tax effect of foreign currency translation adjustments arising during the period	$ 2	$ 1
Tax effect of available-for-sale securities arising during the period	(28)	(12)
Tax effect of qualifying derivatives arising during the period	(62)	(32)
Tax effect of equity investees' other comprehensive income (loss) arising during the period	2	0
Tax effect of available-for-sale securities reclassified to net income	2	5
Tax effect of qualifying derivatives reclassified to net income	87	51
Tax effect of equity investees' other comprehensive income (loss) reclassified to net income	0	0
Tax effect of prior service costs reclassified to net income	(1)	(2)
Tax effect of net actuarial loss reclassified to net income	(4)	(4)
PPL Energy Supply [Member]
Tax effect of available-for-sale securities arising during the period	(28)	(12)
Tax effect of qualifying derivatives arising during the period	(57)	(34)
Tax effect of available-for-sale securities reclassified to net income	2	5
Tax effect of qualifying derivatives reclassified to net income	93	54
Tax effect of equity investees' other comprehensive income (loss) reclassified to net income	0	0
Tax effect of prior service costs reclassified to net income	(1)	(1)
Tax effect of net actuarial loss reclassified to net income	2	0
LKE [Member]
Tax effect of equity investees' other comprehensive income (loss) arising during the period	2	0
Tax effect of net actuarial loss reclassified to net income	0	1
KU [Member]
Tax effect of equity investees' other comprehensive income (loss) arising during the period	$ 2	$ 0