CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Tax effect of foreign currency translation adjustments arising during the period	$ (6)	$ 2
Tax effect of available-for-sale securities arising during the period	(25)	(26)
Tax effect of qualifying derivatives arising during the period	(20)	(50)
Tax effect of equity investees' other comprehensive income (loss) arising during the period	0	2
Tax effect of available-for-sale securities reclassified from accumulated other comprehensive income (loss)	1	0
Tax effect of qualifying derivatives reclassified from accumulated other comprehensive income (loss)	35	75
Tax effect of prior service costs reclassified from accumulated other comprehensive income (loss)	(1)	(1)
Tax effect of net actuarial loss reclassified from accumulated other comprehensive income (loss)	(13)	(4)
PPL Energy Supply LLC [Member]
Tax effect of available-for-sale securities arising during the period	(25)	(26)
Tax effect of qualifying derivatives arising during the period	0	(45)
Tax effect of available-for-sale securities reclassified from accumulated other comprehensive income (loss)	1	0
Tax effect of qualifying derivatives reclassified from accumulated other comprehensive income (loss)	21	81
Tax effect of prior service costs reclassified from accumulated other comprehensive income (loss)	(1)	(1)
Tax effect of net actuarial loss reclassified from accumulated other comprehensive income (loss)	$ (2)	$ 2