Utility Rate Regulation (Details) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended														1 Months Ended																																															1 Months Ended	9 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2011 MW	Sep. 30, 2011	Sep. 30, 2011 MW Kilovolts Gallons	Dec. 31, 2010	Sep. 30, 2011 Generation Supply Charge [Member]		Dec. 31, 2010 Generation Supply Charge [Member]		Sep. 30, 2011 Universal Service Rider [Member]	Dec. 31, 2010 Universal Service Rider [Member]	Sep. 30, 2011 Defined Benefit Plans [Member]	Dec. 31, 2010 Defined Benefit Plans [Member]	Sep. 30, 2011 Taxes Recoverable Through Future Rates [Member]	Dec. 31, 2010 Taxes Recoverable Through Future Rates [Member]	Sep. 30, 2011 Storm Costs [Member]	Dec. 31, 2010 Storm Costs [Member]	Jul. 31, 2011 Unamortized Loss On Debt [Member]	Sep. 30, 2011 Unamortized Loss On Debt [Member]	Dec. 31, 2010 Unamortized Loss On Debt [Member]	Sep. 30, 2011 Interest Rate Swaps [Member]	Dec. 31, 2010 Interest Rate Swaps [Member]	Sep. 30, 2011 Accumulated Cost Of Removal Of Utility Plant [Member]		Dec. 31, 2010 Accumulated Cost Of Removal Of Utility Plant [Member]		Sep. 30, 2011 Coal Contracts [Member]		Dec. 31, 2010 Coal Contracts [Member]		Sep. 30, 2011 Fuel Adjustment Clause [Member]	Dec. 31, 2010 Fuel Adjustment Clause [Member]	Sep. 30, 2011 Other Regulatory Assets [Member]	Dec. 31, 2010 Other Regulatory Assets [Member]	Sep. 30, 2011 Coal Contracts [Member]		Dec. 31, 2010 Coal Contracts [Member]		Sep. 30, 2011 Generation Supply Charge [Member]		Dec. 31, 2010 Generation Supply Charge [Member]		Sep. 30, 2011 Environmental Cost Recovery [Member]	Dec. 31, 2010 Environmental Cost Recovery [Member]	Sep. 30, 2011 Public Utility Realty Tax Act Tax [Member]	Dec. 31, 2010 Public Utility Realty Tax Act Tax [Member]	Sep. 30, 2011 Demand Side Management [Member]	Dec. 31, 2010 Demand Side Management [Member]	Sep. 30, 2011 Transmission Service Charge [Member]	Dec. 31, 2010 Transmission Service Charge [Member]	Sep. 30, 2011 Accumulated Cost Of Removal Of Utility Plant [Member]	Dec. 31, 2010 Accumulated Cost Of Removal Of Utility Plant [Member]	Sep. 30, 2011 Power Purchase Agreement OVEC [Member]		Dec. 31, 2010 Power Purchase Agreement OVEC [Member]		Sep. 30, 2011 Net Deferred Tax Assets [Member]	Dec. 31, 2010 Net Deferred Tax Assets [Member]	Sep. 30, 2011 Act 129 Compliance Rider [Member]	Dec. 31, 2010 Act 129 Compliance Rider [Member]	Sep. 30, 2011 Defined Benefit Plans [Member]	Dec. 31, 2010 Defined Benefit Plans [Member]	Sep. 30, 2011 Other Regulatory Liabilities [Member]	Dec. 31, 2010 Other Regulatory Liabilities [Member]	Sep. 30, 2011 Kentucky August 2011 Storms [Member]	Sep. 30, 2011 Virginia December 2009 Storms [Member]	Sep. 30, 2011 Pennsylvania 2011 Storms [Member]	Sep. 30, 2011 Pennsylvania 2011 Storms [Member]	Sep. 30, 2011 Pennsylvania 2011 Storms [Member]
Regulatory Assets [Line Items]
Current regulatory assets	$ 19,000,000	$ 19,000,000	$ 19,000,000	$ 85,000,000	$ 0	[1]	$ 45,000,000	[1]	$ 3,000,000	$ 10,000,000																				$ 10,000,000	$ 3,000,000	$ 6,000,000	$ 27,000,000
Noncurrent regulatory assets	1,277,000,000	1,277,000,000	1,277,000,000	1,180,000,000							586,000,000	592,000,000	270,000,000	254,000,000	132,000,000	129,000,000		113,000,000	61,000,000	66,000,000	43,000,000	46,000,000	[2]	35,000,000	[2]	14,000,000	[3]	22,000,000	[3]			50,000,000	44,000,000
Unamortized Loss on Debt (Numeric) [Abstract]
Payment for debt extinguishment that created new regulatory asset																	458,000,000
Increase during the period for new assets																	59,000,000
Regulatory Liabilities [Line Items]
Current regulatory liabilities	83,000,000	83,000,000	83,000,000	109,000,000																														12,000,000	[3]	46,000,000	[3]	37,000,000	[1]	0	[1]	8,000,000	12,000,000	3,000,000	10,000,000	10,000,000	10,000,000	1,000,000	8,000,000	646,000,000	623,000,000	118,000,000	[3]	124,000,000	[3]	37,000,000	40,000,000	13,000,000	14,000,000	10,000,000	10,000,000	12,000,000	23,000,000
Noncurrent regulatory liabilities	1,020,000,000	1,020,000,000	1,020,000,000	1,031,000,000																														188,000,000	[3]	213,000,000	[3]																									8,000,000	7,000,000
Regulatory Matter - Storm Costs [Line Items]
Recoverable storm costs																																																																	6,000,000
Number of customers impacted by storm																																																																139,000	30,000
Deferred costs not yet approved by regulator																																																																7,000,000
Amount of regulatory asset established																																																																	6,000,000
Total storm restoration costs incurred																																																																			34,000,000	59,000,000
Storm restoration costs recorded to statement of income																																																																			23,000,000	39,000,000
Total probable insurance recoveries recorded																																																																			12,000,000	26,500,000
Total probable insurance recoveries recorded to statement of income																																																																			7,000,000	16,000,000
Minimum range of costs requested to be deferred																																																																		15,000,000
Maximum range of costs requested to be deferred																																																																		20,000,000
Period over which commission recommended asset recovery be spread over (in years)																																																																	5
Regulatory Matters - Kentucky Activities - Environmental Upgrades (Numeric) [Abstract]
June 2011 request to KPSC of amount for environmental upgrades	2,500,000,000
LG&E portion of total cost of request to KPSC	1,400,000,000
Projected percentage, in hundreths, impact on LG&E's customers rates in 2012	2.30%
Projected percentage, in hundreths, impact on LG&E's customers rates in 2016	19.20%
KU portion of total cost of request to KPSC	1,100,000,000
Projected percentage, in hundreths, impact on KU's customers rates in 2012	1.50%
Projected percentage, in hundreths, impact on KU's customers rates in 2016	12.20%
Regulatory Matters - Kentucky Activities - Integrated Resource Planning (Numeric) [Abstract]
IRP regulation assumption of reductions, in MW, of peak demand by 2017			500
Regulatory Matters - Kentucky Activities - Certificate of Public Convenience and Necessity Filing (Numeric) [Abstract]
Capacity of proposed NGCC (in MW)	640
KU undivided ownership interest in proposed combined cycle turbine (in hundredths)	78.00%
LG&E undivided ownership interest in proposed combined cycle turbine (in hundredths)	22.00%
Number of existing coal-fired units that may be retired in 2015 when replacement capacity is built or purchased	3
Capacity of turbines the company plans to purchase (in MW)	495
Capacity of coal-fired generation units that the company anticipates retiring in 2015 (in MW)	797		797
Combined cost of Bluegrass and NGCC	800,000,000
Regulatory Matters - Virginia Activities - Rate Case (Numeric) [Abstract]
Dollar amount of requested increase (decrease) to electric base rates in Virginia for KU	9,000,000
Percentage increase (decrease) to electric base rates in Virginia for KU (in hundredths)	14.00%
Return on rate base of increase (decrease) of requested increase to electric base rates in Virginia for KU (in hundredths)	8.00%
Return on equity of increase (decrease) of requested increase to electric base rates in Virginia for KU (in hundredths)	11.00%
Number of modifications made by regulator in approving rate case	2
Annual revenue increase resulting from rate case	7,000,000
Recovery period of storm cost regulatory asset approved as part of rate case (in years)	5
Regulatory Matters - Virginia Activities - Levelized Fuel Factor (Numeric) [Abstract]
Period over which under recoveries will be recovered over (in years)			3
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract]
Under Act 129, percentage reduction in electricity consumption by 2011			1.00%
Under Act 129, percentage reduction in electricity consumption by 2013			3.00%
Number of hours that are the benchmark for demand reductions by 2013			100
Under Act 129, percentage reduction in peak demand electricity consumption by 2013			4.50%
Under Act 129, percentage cap on costs that can be recovered for implementation of EE and C plan			2.00%
Number of programs included in EE and C plan			14
Number of components of EE and C Plan company requested permission to modify			2
Maximum number of years the cost of smart meters can be depreciated			15
Estimated cost for studies on smart meter capabilities	38,000,000	38,000,000	38,000,000
The time period covered by cost projection for studies on smart meter capabilities (in years)			5
Minimum term of long term supply contract under Act 129 (in years)			4
Maximum term of long term supply contract under Act 129 (in years)			20
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129			25.00%
Regulatory Matters - Pennsylvania Activities - PUC Investigation of Retail Market (Numeric) [Abstract]
Number of phases of a PUC investigation of retail electricity market			2
Regulatory Matters - International Activities - U.K. Overhead Electricity Networks (Numeric) [Abstract]
Horizontal clearance that requires insulation or relocation of overhead lines in the U.K. (in meters)			3
WPD's projected cost for compliance with overhead electricity standards	124,000,000	124,000,000	124,000,000
Period over which WPD's projected costs to comply with overhead electricity standards are allowed to be recovered in rates (in years)			5
Number of years WPD has to implement vegetation management program			25
Projected costs to implement program for vegetation management	205,000,000	205,000,000	205,000,000
Period over which WPD's projected costs for vegetation management program are allowed to be recovered in rates (in years)			5
Liability for tree trimming recorded as part of purchase accounting		$ 69,000,000
Regulatory Matters - International Activities - New U.K. Pricing Model (Numeric) [Abstract]
Period, in years, in which the price control formula is normally reviewed			5
Proposed price review period (in years)			8

[1] PPL Electric's generation supply charge recovery mechanism moved from an undercollected status at December 31, 2010 to an overcollected status at September 30, 2011, reflecting the impacts of changes in customer billing cycles, the timing of rate reconciliation filings, the levels of customers choosing alternative energy suppliers and other factors. Because customer rates are designed to collect the costs of PPL Electric's energy purchases to meet its PLR requirements, there is minimal impact on earnings.

[2] The December 31, 2010 balance of accumulated cost of removal of utility plant was reclassified from "Accumulated depreciation - regulated utility plant" to noncurrent "Regulatory assets" on the Balance Sheets. These costs will continue to be included in future rate proceedings.

[3] These regulatory assets and liabilities were recorded as offsets to certain intangible assets and liabilities that were recorded at fair value upon the acquisition of LKE.