SCHEDULE I - NOTES TO CONDENSED UNCONSOLIDATED FINANCIAL STATEMENTS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Unconsolidated Financial Statements [Line Items]
Charge recorded in discontinued operations relating to certain indemnification, pre-tax		$ (74)	$ 66
LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Term of guarantee (in years)	12
Expiration date minimum	2021
Maximum exposure of guarantee related to terminated lease specific to operational, regulatory and environmental issues	200
Maximum exposure of other guarantees expiring related to a terminated lease	100
Expiration date maximum	2023
Charge recorded in discontinued operations relating to certain indemnification, pre-tax	9
Charge recorded in discontinued operations relating to certain indemnification, after-tax	5
LG&E and KU Energy LLC Unconsolidated | LKE Guarantee [Member] | Indemnification Guarantee [Member] | Indemnification Of Lease Termination And Other Divestitures [Member]
Condensed Unconsolidated Financial Statements [Line Items]
Term of guarantee (in years)	12
Expiration date minimum	2021
Maximum exposure of guarantee related to terminated lease specific to operational, regulatory and environmental issues	200
Maximum exposure of other guarantees expiring related to a terminated lease	100
Expiration date maximum	2023
Charge recorded in discontinued operations relating to certain indemnification, pre-tax	9
Charge recorded in discontinued operations relating to certain indemnification, after-tax	$ 5