Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009		Dec. 31, 2008
Comprehensive Income (Details) [Line Items]
Foreign currency translation adjustments	$ (243)		$ (195)		$ (136)		$ (237)
Available-for-sale securities	88		86		62		18
Qualifying derivatives	527		695		602		(21)
Equity investees' OCI	1		(2)		(2)		(3)
Defined benefits plans:
Prior service cost	(25)		(32)		(61)		(75)
Actuarial loss	(1,137)		(1,032)		(993)		(657)
Transition asset (obligation)	1		1		(9)		(10)
Total Accumulated Other Comprehensive Loss, Net of Tax	(788)		(479)		(537)		(985)
Utility Revenue (Details) [Abstract]
Domestic electric revenue	4,674	[1]	2,941	[1]	3,218	[1]
U.K. electric revenue	1,618	[2]	727	[2]	684	[2]
Domestic natural gas revenue	0		0		0
Total	6,292		3,668		3,902
Revenue Recognition (Numeric) [Abstract]
Costs in excess of billings on uncompleted contracts or programs	15		9
Billings in excess of cost	67		70
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	872		617
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	209		66
Property, Plant and Equipment (Numeric) [Abstract]
Interest costs, capitalized during the period	51		30		44
Gross carrying amount	290		213
Accumulated amortization	98		70
Capitalized computer software, amortization	39		21		13
Defined Benefits (Numeric) [Abstract]
Minimum percentage of gains and losses under the accelerated method that are amortized on a straight line basis (in hundredths)	10.00%
Maximum percentage of gains and losses under the accelerated that are amortized on a straight line basis (in hundredths)	30.00%
Percentage in excess of gains and losses equal to the plan's projected benefit obligation to use accelerated amortization (in hundredths)	30.00%
Fuel, Materials and Supplies (Details) [Line Items]
Fuel, materials and supplies on the Balance Sheet	654		643
Foreign Currency Translation (Numeric) [Abstract]
Foreign currency translation impacting OCI	15
Fuel [Member]
Fuel, Materials and Supplies (Details) [Line Items]
Fuel, materials and supplies on the Balance Sheet	246		260
Natural Gas Stored Underground [Member]
Fuel, Materials and Supplies (Details) [Line Items]
Fuel, materials and supplies on the Balance Sheet	73	[3]	81	[3]
Material and Supplies [Member]
Fuel, Materials and Supplies (Details) [Line Items]
Fuel, materials and supplies on the Balance Sheet	335		302
Regulated Utility Plant [Member]
Depreciation (Details) [Abstract]
Weighted-average rates (in hundredths)	3.03%	[4]	3.27%	[4]
Non-regulated PPE - Generation [Member]
Depreciation (Details) [Abstract]
Weighted-average rates (in hundredths)	2.88%		2.76%
Margin Deposits Posted To Counterparties [Member]
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	137	[5]	14	[5]
Cash Collateral Posted To Counterparties [Member]
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	29	[6]	19	[6]
Low Carbon Network Fund [Member]
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	9	[7]	0
Captive Insurance Reserves [Member]
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	6	[8]	6	[8]
Funds Deposited With A Trustee [Member]
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	12	[9]	13	[9]
Other [Member]
Restricted Cash and Cash Equivalents (Numeric) [Line Items]
Restricted cash and cash equivalents	16		14
Allowance For Doubtful Accounts [Member]
Allowance for Doubtful Accounts (Details) [Roll Forward]
Balance at beginning of period	55		37		40
Additions charged to income	65	[10],[11]	42		30
Additions charged to other accounts	0		7	[12]	0
Deductions	66	[10],[13],[14]	31	[13]	33	[13]
Balance at end of period	54	[10]	55		37
Other Comprehensive Income [Member]
Comprehensive Income (Details) [Line Items]
Foreign currency translation adjustments	(48)		(59)		101
Available-for-sale securities	2		24		45
Qualifying derivatives	(168)		93		623
Equity investees' OCI	3		0		1
Defined benefits plans:
Prior service cost	7		29		14
Actuarial loss	(105)		(39)		(336)
Transition asset (obligation)	0		10		1
Total Accumulated Other Comprehensive Loss, Net of Tax	(309)		58		449
Cumulative Effect Adjustment [Member]
Comprehensive Income (Details) [Line Items]
Foreign currency translation adjustments					0
Available-for-sale securities					(1)	[15]
Qualifying derivatives					0
Equity investees' OCI					0
Defined benefits plans:
Prior service cost					0
Actuarial loss					0
Transition asset (obligation)					0
Total Accumulated Other Comprehensive Loss, Net of Tax					$ (1)	[15]

[1] Represents revenue from regulated generation, transmission and/or distribution in Pennsylvania, Kentucky, Virginia and Tennessee, including regulated wholesale revenue.

[2] Represents electric revenue from the operation of WPD's distribution networks. 2011 includes eight months of revenue for WPD Midlands, which are recorded on a one-month lag.

[3] The majority of LKE's and LG&E's natural gas stored underground is held to serve native load. The majority of PPL Energy Supply's natural gas stored underground is available for resale.

[4] For PPL, LKE, LG&E and KU, as a result of the acquisition of LKE, the original cost for PP&E is its fair value on November 1, 2010, which approximated net book value. This fair value adjustment resulted in lowering the original cost basis of LKE's, LG&E's and KU's PP&E, thus impacting the calculation of the weighted-average depreciation rate.

[5] Deposits posted to counterparties associated with trading activities.

[6] Cash collateral posted to counterparties related to interest rate swap contracts.

[7] Funds received by WPD, which are to be spent on approved initiatives to support a low carbon environment.

[8] Funds required by law to be held by WPD's captive insurance company to meet claims.

[9] Funds deposited with a trustee to defease PPL Electric's 1945 First Mortgage Bonds. See Note 7 for additional information.

[10] Includes amounts associated with LKE activity since the November 1, 2010 acquisition date. See Note 10 for additional information related to the acquisition of LKE.

[11] Includes amounts related to the SMGT bankruptcy. See Note 15 for additional information.

[12] Primarily related to capital projects, thus the provision was recorded as an adjustment to construction work in progress.

[13] Primarily related to uncollectible accounts written off.

[14] Includes amounts related to the June 2011, FERC approved settlement agreement between PPL and California ISO related to the sales made to the California ISO during the period October 2000 through June 2001 that were not paid to PPL subsidiaries. Therefore, the receivable and the related allowance for doubtful accounts were reversed and the settlement recorded.

[15] Recorded in connection with the adoption of accounting guidance related to the recognition and presentation of other-than-temporary impairments.