Utility Rate Regulation (Details) (USD $)	1 Months Ended	3 Months Ended	12 Months Ended		12 Months Ended		1 Months Ended	12 Months Ended	1 Months Ended		1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended		12 Months Ended																										12 Months Ended																					12 Months Ended
	Apr. 30, 2011	Sep. 30, 2010	Dec. 31, 2011 MW	Dec. 31, 2010	Dec. 31, 2011 Hurricane Cost Recovery [Member]	Dec. 31, 2010 Hurricane Cost Recovery [Member]	Sep. 30, 2009 Ice Storm Cost Recovery [Member]	Dec. 31, 2011 Ice Storm Cost Recovery [Member]	Aug. 31, 2011 Kentucky August 2011 Storms [Member]	Sep. 30, 2011 Kentucky August 2011 Storms [Member]	Mar. 31, 2011 Virginia December 2009 Storms [Member]	Dec. 31, 2009 Virginia December 2009 Storms [Member]	Dec. 31, 2011 Pennsylvania 2011 Storms [Member]	Dec. 31, 2011 Pennsylvania 2011 Storms [Member]	Dec. 31, 2011 Defined Benefit Plan Combined Asset And Liability [Member]	Dec. 31, 2011 Accumulated Cost Of Removal Of Utility Plant Combined Asset And Liability [Member]	Dec. 31, 2011 Environmental Cost Recovery Combined Asset And Liability [Member]	Dec. 31, 2011 Gas Supply Clause Combined Asset And Liability [Member]	Dec. 31, 2011 Fuel Adjustments Combined Asset And Liability [Member]	Dec. 31, 2011 Coal Contracts [Member]		Dec. 31, 2010 Coal Contracts [Member]		Dec. 31, 2011 Generation Supply Charge [Member]		Dec. 31, 2011 Environmental Cost Recovery [Member]	Dec. 31, 2010 Environmental Cost Recovery [Member]	Dec. 31, 2011 Public Utility Realty Tax Act Tax [Member]	Dec. 31, 2010 Public Utility Realty Tax Act Tax [Member]	Dec. 31, 2011 Gas Supply Clause [Member]	Dec. 31, 2010 Gas Supply Clause [Member]	Dec. 31, 2011 Transmission Service Charge [Member]	Dec. 31, 2010 Transmission Service Charge [Member]	Dec. 31, 2011 Accumulated Cost Of Removal Of Utility Plant [Member]	Dec. 31, 2010 Accumulated Cost Of Removal Of Utility Plant [Member]	Dec. 31, 2011 Power Purchase Agreement OVEC [Member]		Dec. 31, 2010 Power Purchase Agreement OVEC [Member]		Dec. 31, 2011 Net Deferred Tax Assets [Member]	Dec. 31, 2010 Net Deferred Tax Assets [Member]	Dec. 31, 2011 Act 129 Compliance Rider [Member]	Dec. 31, 2010 Act 129 Compliance Rider [Member]	Dec. 31, 2011 Defined Benefit Plans [Member]	Dec. 31, 2010 Defined Benefit Plans [Member]	Dec. 31, 2011 Other Regulatory Liabilities [Member]	Dec. 31, 2010 Other Regulatory Liabilities [Member]	Dec. 31, 2011 Generation Supply Charge [Member]	Dec. 31, 2010 Generation Supply Charge [Member]		Dec. 31, 2011 Universal Service Rider [Member]	Dec. 31, 2010 Universal Service Rider [Member]	Dec. 31, 2011 Gas Supply Clause [Member]	Dec. 31, 2010 Gas Supply Clause [Member]	Dec. 31, 2011 Fuel Adjustment Clause [Member]	Dec. 31, 2010 Fuel Adjustment Clause [Member]	Dec. 31, 2011 Defined Benefit Plans [Member]	Dec. 31, 2010 Defined Benefit Plans [Member]	Dec. 31, 2011 Taxes Recoverable Through Future Rates [Member]	Dec. 31, 2010 Taxes Recoverable Through Future Rates [Member]	Dec. 31, 2011 Storm Costs [Member]	Dec. 31, 2010 Storm Costs [Member]	Dec. 31, 2011 Unamortized Loss On Debt [Member]	Dec. 31, 2010 Unamortized Loss On Debt [Member]	Dec. 31, 2011 Interest Rate Swaps [Member]	Dec. 31, 2010 Interest Rate Swaps [Member]	Dec. 31, 2011 Accumulated Cost Of Removal Of Utility Plant [Member]		Dec. 31, 2010 Accumulated Cost Of Removal Of Utility Plant [Member]		Dec. 31, 2011 Coal Contracts [Member]		Dec. 31, 2010 Coal Contracts [Member]		Dec. 31, 2011 Asset Retirement Obligation Costs [Member]	Dec. 31, 2010 Asset Retirement Obligation Costs [Member]	Dec. 31, 2011 Other Regulatory Assets [Member]	Dec. 31, 2010 Other Regulatory Assets [Member]
Regulatory Assets [Line Items]
Current regulatory assets			$ 9,000,000	$ 85,000,000																																												$ 0	$ 45,000,000	[1]	$ 0	$ 10,000,000	$ 6,000,000	$ 4,000,000	$ 3,000,000	$ 3,000,000																					$ 0	$ 23,000,000
Noncurrent regulatory assets			1,349,000,000	1,180,000,000																																																					615,000,000	592,000,000	289,000,000	254,000,000	154,000,000	129,000,000	110,000,000	61,000,000	69,000,000	43,000,000	53,000,000	[2]	35,000,000	[2]	11,000,000	[3]	22,000,000	[3]	18,000,000	9,000,000	30,000,000	35,000,000
Regulatory Assets and Liabilities - Unamortized Loss on Debt (Numeric) [Abstract]
Amortization end date																																																															Dec. 31, 2036
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			73,000,000	109,000,000																0		46,000,000	[3]	42,000,000	[1]	7,000,000	12,000,000	0	10,000,000	6,000,000	9,000,000	2,000,000	8,000,000													16,000,000	24,000,000
Noncurrent regulatory liabilities			1,010,000,000	1,031,000,000																180,000,000	[3]	213,000,000	[3]											651,000,000	623,000,000	116,000,000	[3]	124,000,000	[3]	39,000,000	40,000,000	7,000,000	14,000,000	9,000,000	10,000,000	8,000,000	7,000,000
Regulatory Assets and Liabilities - Act 129 Compliance Rider (Numeric) [Abstract]
Maximum recoverable cost																																										250,000,000
Regulatory Assets And Liabilities [Line Items]
Amortization period																five-year	12 months	18 months	12 months
Regulatory Assets and Liabilities - Defined Benefit Plans (Numeric) [Abstract]
Regulatory asset costs expected to be amortized into net periodic defined benefit costs in the next year															44,000,000
Regulatory Matter - Storm Costs [Line Items]
Recoverable storm costs					26,000,000		101,000,000
Number of customers impacted by storm									139,000			30,000
Deferred costs not yet approved by regulator										8,000,000
Amount of regulatory asset established								12,000,000			6,000,000		25,000,000
Total storm restoration costs incurred														84,000,000
Storm restoration costs recorded to statement of income														54,000,000
Period over which storm costs will be recovered over (in years)						10					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 approved request to KPSC			1,400,000,000
KU portion of total cost of approved request to KPSC			900,000,000
Return on equity for approved projects remaining from earlier ECR plans			10.63%
Return on equity for approved projects in the 2011 ECR proceedings			10.10%
Capital costs deferred in connection with certain environmental upgrades at the E.W. Brown plant			200,000,000
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
LG&E undivided ownership interest in proposed combined cycle turbine			22.00%
KU undivided ownership interest in proposed combined cycle turbine			78.00%
Capacity of turbines the company plans to purchase (in MW)			495
LG&E's undivided ownership interest in purchase of three turbines			69.00%
KU's undivided ownership interest in purchase of three turbines			31.00%
Number of existing coal-fired units that may be retired in 2015 when replacement capacity is built or purchased			3
Capacity of coal-fired generation units that the company anticipates retiring in 2015 (in MW)			797
Combined cost of Bluegrass and NGCC			800,000,000
Regulatory Matters - Kentucky Activities - PPL's Acquisition of LKE (Numeric) [Abstract]
Rate of return on common equity if exceeded triggers costs savings being returned to customers			10.75%
Regulatory Matters - Virginia Activities - Integrated Resource Planning (Numeric) [Abstract]
Virginia Integrated Resource Planning Peak Demand Decline Assumption			500
Regulatory Matters - Virginia Activities - Virginia 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%
Under Act 129, percentage reduction in peak demand electricity consumption by 2013			4.50%
Number of hours that are the benchmark for demand reductions by 2013			100
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
Maximum amount of recovery of proposed plan rate mechanism			250,000,000
Number of components of EE and C Plan company requested permission to modify			2
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 - Smart Meter Rider (Numeric) [Abstract]
Maximum number of years the cost of smart meters can be depreciated			15
Estimated cost for studies on smart meter capabilities		38,000,000
The time period covered by cost projection for studies on smart meter capabilities (in years)		5
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 - Federal Matters - FERC Formula Rates (Numeric) [Abstract]
Requested recovery period (in years)			34 year
Regulatory asset amount recorded related to certain deferred state tax assets			51,000,000
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			120,000,000
Period over which WPD's projected costs to comply with overhead electricity standards are allowed to be recovered in rates (in years)			5
Projected costs to implement program for vegetation management			198,000,000
Period over which WPD's projected costs for vegetation management program are allowed to be recovered in rates (in years)			25
Liability for tree trimming recorded as part of purchase accounting	68,000,000		57,000,000
Regulatory Matters - International Activities - Ofgem Review of Line Loss Calculation (Numeric) [Abstract]
Line Loss Prior Price Control			$ 170,000,000
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 December 31, 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.