Financing Activities (Short-term Debt) (Details) (Commercial Paper [Member], USD $) In Millions, unless otherwise specified	9 Months Ended						9 Months Ended
	Sep. 30, 2012 PPL Energy Supply [Member]	Mar. 31, 2011 PPL Energy Supply [Member]	Sep. 30, 2012 PPL Electric [Member]	Apr. 30, 2012 PPL Electric [Member]	Sep. 30, 2012 LGE [Member]	Sep. 30, 2012 KU [Member]	Sep. 30, 2012 PPL Energy Supply LLC [Member]	Mar. 31, 2011 PPL Energy Supply LLC [Member]	Sep. 30, 2012 PPL Electric Utilities Corp [Member]	Apr. 30, 2012 PPL Electric Utilities Corp [Member]	Sep. 30, 2012 LG And E And KU Energy LLC [Member] LGE [Member]	Sep. 30, 2012 LG And E And KU Energy LLC [Member] KU [Member]	Sep. 30, 2012 Louisville Gas And Electric Co [Member]	Sep. 30, 2012 Kentucky Utilities Co [Member]
Short-term Debt [Line Items]
Capacity	$ 750	$ 500	$ 300	$ 200	$ 250	$ 250	$ 750	$ 500	$ 300	$ 200	$ 250	$ 250	$ 250	$ 250
Commercial paper outstanding	$ 355						$ 355
Weighted-average interest rate on outstanding commercial paper	0.48%						0.48%