Income Taxes (Unrecognized Tax Benefits and Tax Litigation) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Unrecognized Tax Benefits [Abstract]
Beginning of period	$ 92	$ 145
Additions based on tax positions of prior years		4
Reductions based on tax positions of prior years		(27)
Additions based on tax positions related to the current year		1
Lapse of applicable statutes of limitations	(2)	(2)
End of period	90	121
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Details) [Abstract]
Total amount unrecognized tax benefits may increase in next 12 months	10
Total amount unrecognized tax benefits may decrease in next 12 months	88
Total unrecognized tax benefits and related effects that, if recognized, would decrease the effective tax rate	37	41
Tax Litigation Numeric [Abstract]
Benefit from favorable United States Tax Court decision on deductibility of United Kingdom windfall profit tax	42
Expense from reversal by United States Court of Appeals for the Third Circuit on deductibility of United Kingdom windfall profit tax	39
PPL Energy Supply LLC [Member]
Unrecognized Tax Benefits [Abstract]
Beginning of period	30	28
Additions based on tax positions of prior years		4
Reductions based on tax positions of prior years		(1)
End of period	30	31
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Details) [Abstract]
Total amount unrecognized tax benefits may increase in next 12 months
Total amount unrecognized tax benefits may decrease in next 12 months	30
Total unrecognized tax benefits and related effects that, if recognized, would decrease the effective tax rate	13	14
PPL Electric Utilities Corp [Member]
Unrecognized Tax Benefits [Abstract]
Beginning of period	26	73
Reductions based on tax positions of prior years		(26)
Additions based on tax positions related to the current year		1
Lapse of applicable statutes of limitations	(2)	(2)
End of period	24	46
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Details) [Abstract]
Total amount unrecognized tax benefits may increase in next 12 months	10
Total amount unrecognized tax benefits may decrease in next 12 months	22
Total unrecognized tax benefits and related effects that, if recognized, would decrease the effective tax rate	$ 3	$ 6