Income and Other Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Income (Loss) from Continuing Operations (Details) [Abstract]
Domestic income	$ 1,715,000,000		$ 952,000,000		$ 207,000,000
Foreign income	486,000,000		287,000,000		331,000,000
Income (Loss) from Continuing Operations Before Income Taxes	2,201,000,000		1,239,000,000		538,000,000
Deferred Tax Assets
Deferred investment tax credits	113,000,000		45,000,000
Regulatory obligations	149,000,000		205,000,000
Accrued pension costs	325,000,000		316,000,000
Accrued litigation costs	2,000,000		31,000,000
Federal loss carryforwards	305,000,000		314,000,000
State loss carryforwards	272,000,000		269,000,000
Federal tax credit carryforwards	240,000,000		169,000,000
Foreign capital loss carryforwards	578,000,000		377,000,000
Foreign loss carryforwards	7,000,000		0
Foreign - pensions	74,000,000		87,000,000
Foreign - regulatory obligations	67,000,000		0
Foreign - other	21,000,000		8,000,000
Contributions in aid of construction	133,000,000		152,000,000
Domestic - other	227,000,000		219,000,000
Valuation allowances	(724,000,000)		(464,000,000)
Total deferred tax assets	1,789,000,000		1,728,000,000
Deferred Tax Liabilities
Plant - net	3,465,000,000		3,010,000,000
Taxes recoverable through future rates	137,000,000		105,000,000
Unrealized gains on qualifying derivatives	331,000,000		298,000,000
Other regulatory assets	234,000,000		321,000,000
Regulatory undercollections	0		22,000,000
Reacquired debt costs	93,000,000		25,000,000
Foreign - plant	975,000,000		526,000,000
Foreign - other	22,000,000		36,000,000
Domestic - other	103,000,000		95,000,000
Total deferred tax liabilities	5,360,000,000		4,438,000,000
Net deferred tax liability	(3,571,000,000)		(2,710,000,000)
Loss carryforwards
State net operating loss carryforwards associated with LKE			1,000,000,000
Valuation Allowances and Reserves (Details) [Roll Forward]
Valuation allowance recorded against certain deferred tax assets as a result of the WPD Midlands acquisition	101,000,000
Reduction of the valuation allowance as a result of the reduction in the UK statutory income tax rate	35,000,000
Valuation allowance reduction related to state net operating loss carryforwards (in dollars per share)			$ 0.17
Valuation allowance reduction related to state net operating loss carryforwards related to expiration of generation rate caps			72,000,000		13,000,000
Permanently reinvested cumulative undistributed foreign earnings	1,200,000,000		837,000,000
Income Tax Expense (Benefit)
Current - Federal	54,000,000		(51,000,000)		(72,000,000)
Current - State	(20,000,000)		43,000,000		14,000,000
Current - Foreign	73,000,000		20,000,000		41,000,000
Total Current Expense (Benefit)	107,000,000		12,000,000		(17,000,000)
Deferred - Federal	558,000,000		358,000,000		130,000,000
Deferred - State	127,000,000		(82,000,000)		(10,000,000)
Deferred - Foreign	(23,000,000)		(9,000,000)		16,000,000
Total Deferred Expense	662,000,000		267,000,000		136,000,000
Investment tax credit, net - Federal	(10,000,000)		(5,000,000)		(14,000,000)
Tax benefit of operating loss carryforwards [Abstract]
Deferred - Federal	(30,000,000)		6,000,000		0
Deferred - State	(38,000,000)		(17,000,000)		0
Tax Benefit of Operating Loss Carryforwards	(68,000,000)		(11,000,000)		0
Total income tax from continuing operations	691,000,000	[1]	263,000,000	[1]	105,000,000	[1]
Total income tax expense - Federal	572,000,000		308,000,000		44,000,000
Total income tax expense - State	69,000,000		(56,000,000)		4,000,000
Total income tax expense - Foreign	50,000,000		11,000,000		57,000,000
Total income tax expense from continuing operations	691,000,000	[1]	263,000,000	[1]	105,000,000	[1]
Current and deferred federal, state and foreign tax expense (benefit) recorded to Discontinued Operations	2,000,000		(6,000,000)		46,000,000
Realized tax benefits related to stock-based compensation, recorded as an increase to capital in excess of par	3,000,000
Tax benefits related to the issuance of the Purchase Contracts recorded an increase to capital in excess of par	5,000,000		10,000,000
Federal, state, and foreign tax expense (benefit) recorded to OCI	(137,000,000)		83,000,000		358,000,000
Amount excluded from related to valuation allowances for state deferred taxes	3,000,000
Reconciliation of Income Tax Expense
Federal income tax on Income (Loss) from Continuing Operations Before Income Taxes at statutory tax rate - 35%	770,000,000		434,000,000		188,000,000
Federal statutory tax rate (in hundredths)	35.00%
Increase (decrease) due to:
State income taxes, net of federal income tax benefit	63,000,000		36,000,000		10,000,000
State valuation allowance adjustments	36,000,000	[2]	(65,000,000)	[2]	(13,000,000)	[2]
Impact of lower U.K. income tax rates	(41,000,000)		(20,000,000)		(23,000,000)
U.S. income tax on foreign earnings - net of foreign tax credit	(26,000,000)	[3]	34,000,000	[3]	(16,000,000)	[3]
Federal and state tax reserve adjustments	39,000,000	[4]	(60,000,000)	[4]	(5,000,000)
Foreign tax reserve adjustments	(141,000,000)	[5]	0		17,000,000	[5]
Federal and state income tax return adjustments	(17,000,000)	[6]	(3,000,000)		21,000,000	[6]
Domestic manufacturing deduction	0		(11,000,000)	[7]	(3,000,000)	[6]
Health Care Reform	0		8,000,000	[8]	0
Foreign losses resulting from restructuring	0		(261,000,000)	[5]	(46,000,000)	[5]
Enactment of U.K.'s Finance Act of 2010 and 2011	(69,000,000)	[9]	(18,000,000)	[9]	0
Federal income tax credits	(13,000,000)	[10]	(12,000,000)	[10]	(2,000,000)
Depreciation not normalized	(20,000,000)	[2]	(3,000,000)	[2]	(1,000,000)	[2]
Foreign valuation allowance adjustments	147,000,000	[5]	215,000,000	[5]	0
State deferred tax rate change	(26,000,000)	[11]	0		0
Foreign income tax return adjustments	0		0		0
Amortization of investment tax credit	0		0		0
Nondeductible acquisition-related costs	0		0		0
Other	(11,000,000)		(11,000,000)		(22,000,000)
Total increase (decrease)	(79,000,000)		(171,000,000)		(83,000,000)
Total income taxes from continuing operations	691,000,000		263,000,000		105,000,000
Effective income tax rate	31.40%		21.20%		19.50%
Bonus depreciation percentage	100.00%
Deferred tax expense recorded due to state clarification on treatment of bonus depreciation	43,000,000
Net operating loss limitation	20.00%
Tax (benefit) recorded due to U.K. pension contributions	(28,000,000)
(Benefit) from favorable U.S. Tax Court decision on deductibility of U.K. windfall profit tax			(42,000,000)
Depreciable useful life for tax purposes of street lighting assets (in years)	7
(Benefit) from favorable U.S. Tax Court decision on depreciable useful lives of street lighting			(7,000,000)
(Benefit) recorded related to stranded cost securitization included in change in federal and state income tax reserves	(6,000,000)		(7,000,000)		(6,000,000)
(Benefit) related to reversal of foreign tax reserves for capital losses	(147,000,000)
Expense recorded related to losses resulting from restructuring in the U.K.					46,000,000
(Benefit) recorded related to the resolution of of a tax dispute					(29,000,000)
Benefit related to 2010 federal and state tax return adjustments related to domestic manufacturing deduction	7,000,000
Benefit related to 2010 federal and state tax return adjustments related to the flow through impact of Pennsylvania regulated state tax depreciation	3,000,000
Federal and state income tax return adjustments related to Internal Revenue Code section 481					24,000,000
U.K. statutory income tax rate in effect during period prior to a change	27.00%		28.00%
U.K. Statutory income tax rate reduction	26.00%
U.K. Statutory income tax rate reduction for next year	25.00%
Taxes, other than income
State gross receipts	140,000,000		145,000,000		187,000,000
State utility realty	(9,000,000)		5,000,000		5,000,000
State capital stock	18,000,000		6,000,000		6,000,000
Foreign property	113,000,000		52,000,000		57,000,000
Domestic property and other	64,000,000		30,000,000		25,000,000
Total	326,000,000		238,000,000		280,000,000
Unrecognized Tax Benefits (Details) [Roll Forward]
Beginning of period	251,000,000		212,000,000
Additions based on tax positions of prior years	40,000,000		68,000,000
Reductions based on tax positions of prior years	(160,000,000)		(50,000,000)
Additions based on tax positions related to the current year	25,000,000		43,000,000
Reductions based on tax positions related to the current year	(4,000,000)		(2,000,000)
Settlements increases	0		17,000,000
Lapse of applicable statutes of limitations	(10,000,000)		(8,000,000)
Acquisition of LKE	0		3,000,000
Effects of foreign currency translation	3,000,000		2,000,000
End of period	145,000,000		251,000,000		212,000,000
Unrecognized Tax Benefits - Probable Increase (Decrease) Next 12 Months (Numeric) [Line Items]
Total amount unrecognized tax benefits may increase in next 12 months	43,000,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	129,000,000
Total unrecognized tax benefits and related indirect effects that, if recognized, would decrease the effective tax rate	41,000,000		183,000,000
Open Tax Positions - Accrued Interest (Numeric) [Abstract]
Accrued interest (payable) receivable related to tax positions	(20,000,000)		7,000,000
Open Tax Positions - Interest and Penalties (Numeric) [Abstract]
Interest and penalties expense (benefit) related to tax positions	27,000,000		(39,000,000)		1,000,000
Valuation Allowance Of Operating Loss Carryforwards [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	464,000,000		312,000,000		285,000,000
Additions charged to income	190,000,000		221,000,000		24,000,000
Additions charged to other accounts	112,000,000	[12]	6,000,000	[13]	17,000,000	[14]
Deductions	42,000,000	[15]	75,000,000	[16]	14,000,000	[17]
Balance at end of period	724,000,000		464,000,000		312,000,000
Investment Tax Credit [Member]
Credit carryforwards
Credit carryforwards, amount	180,000,000		125,000,000	[18]
Expiration	2025-2031
Alternative Minimum Tax Credit [Member]
Credit carryforwards
Credit carryforwards, amount	20,000,000		20,000,000	[18]
Expiration	Indefinite
Foreign Tax Credit [Member]
Credit carryforwards
Credit carryforwards, amount	12,000,000		0
Expiration	2017-2021
Other [Member]
Credit carryforwards
Credit carryforwards, amount	28,000,000		24,000,000	[18]
Expiration	2016-2031
Federal [Member]
Loss carryforwards
Net operating losses	876,000,000		799,000,000	[18]
Capital losses	0		155,000,000	[18]
Expiration - operating losses	2028-2031
Expiration - capital losses	2011-2014
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	1997 and prior
State [Member]
Loss carryforwards
Net operating losses	4,537,000,000		4,168,000,000	[19]
Capital losses	137,000,000		181,000,000	[19]
Expiration - operating losses	2012-2031
Expiration - capital losses	2011-2015
State net capital loss carryforwards associated with LKE			163,000,000
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2004 and prior
Foreign [Member]
Loss carryforwards
Net operating losses	28,000,000		0
Capital losses	2,311,000,000	[20]	1,395,000,000
Expiration - operating losses	Indefinite
Expiration - capital losses	Indefinite
Foreign capital loss carryforwards associated with WPD Midlands	$ 456,000,000
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2009 and prior	[21]
Years no longer subject for recently acquired subsidiary	2007 and prior years
Kentucky - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2006 and prior
Montana - State [Member]
Income Tax Examination (Details) [Line Items]
Income tax examination, year(s) no longer under examination	2008 and prior

[1] Excludes current and deferred federal, state and foreign tax expense (benefit) recorded to Discontinued Operations of $2 million in 2011, $(6) million in 2010 and $46 million in 2009. Excludes realized tax expense (benefits) related to stock-based compensation, recorded as a decrease (increase) to additional paid-in capital of $3 million in 2011 and insignificant amounts in 2010 and 2009. Excludes tax benefits related to the issuance costs of the Purchase Contracts, recorded as an increase to additional paid-in capital in the amount of $5 million in 2011 and $10 million in 2010, offset by an insignificant amount of related valuation allowances for state deferred taxes in 2011. Also excludes federal, state, and foreign tax expense (benefit) recorded to OCI of $(137) million in 2011, $83 million in 2010 and $358 million in 2009, and related valuation allowances for state deferred taxes in the amount of $3 million for 2011.

[2] During 2011, the Pennsylvania Department of Revenue issued interpretive guidance on the treatment of bonus depreciation for Pennsylvania income tax purposes. In accordance with Corporation Tax Bulletin 2011-01, Pennsylvania allows 100% bonus depreciation for qualifying assets in the same year bonus depreciation is allowed for Federal income tax purposes. Due to the decrease in taxable income related to bonus depreciation and a decrease in projected future taxable income, PPL recorded $43 million in state deferred income tax expense related to deferred tax valuation allowances. Additionally, the 100% Pennsylvania bonus depreciation deduction created a current state income tax benefit for the flow-through impact of Pennsylvania regulated state tax depreciation. Pennsylvania H.B. 1531, enacted in October 2009, increased the net operating loss limitation to 20% of taxable income for tax years beginning in 2010. During 2009, based on the projected revenue increase due to the expiration of the Pennsylvania generation rate caps in 2010, PPL recorded a $13 million state deferred income tax benefit related to the reversal of deferred tax valuation allowances for a portion of its Pennsylvania net operating losses. During 2010, PPL recorded an additional $72 million state deferred income tax benefit related to the reversal of deferred tax valuation allowances related to the future projections of taxable income over the remaining carryforward period of the net operating losses.

[3] During 2011, PPL recorded a $28 million federal income tax benefit related to U.K. pension contributions. During 2010, PPL recorded additional U.S. income tax expense resulting from increased taxable dividends and certain restructuring of U.K. entities.

[4] In 1997, the U.K. imposed a Windfall Profits Tax (WPT) on privatized utilities, including WPD. PPL filed its tax returns for years subsequent to its 1997 and 1998 claims for refund on the basis that the U.K. WPT was creditable. In September 2010, the U.S. Tax Court (Tax Court) ruled in PPL's favor in a dispute with the IRS, concluding that the U.K. WPT is a creditable tax for U.S. tax purposes. As a result and with the finalization of other issues, PPL recorded a $42 million tax benefit in 2010. In January 2011, the IRS appealed the Tax Court's decision to the U.S. Court of Appeals for the Third Circuit (Third Circuit). In December 2011, the Third Circuit issued its opinion reversing the Tax Court's decision and holding that the U.K. WPT is not a creditable tax. As a result of the Third Circuit's adverse determination, PPL recorded a $39 million expense in 2011. On February 27, 2012, PPL filed with the Third Circuit a petition for rehearing of its opinion on this matter. In July 2010, the U.S. Tax Court ruled in PPL's favor in a dispute with the IRS, concluding that street lighting assets are depreciable for tax purposes over seven years. As a result, PPL recorded a $7 million tax benefit to federal and state income tax reserves and related deferred income taxes. The IRS did not appeal this decision. During 2011, 2010 and 2009, PPL recorded a $6 million, $7 million and $6 million tax benefit to federal and state income tax reserves related to stranded cost securitization.

[5] During 2011, WPD reached an agreement with the HM Revenue & Customs, the U.K. tax authority, related to the amount of the capital losses that resulted from prior years' restructuring in the U.K. and recorded a $147 million foreign tax benefit for the reversal of tax reserves related to the capital losses. Additionally, WPD recorded a $147 million valuation allowance for the amount of capital losses that, more likely than not, will not be utilized. During 2010, PPL recorded a $261 million foreign tax benefit in conjunction with losses resulting from restructuring in the U.K. A portion of these losses offset tax on a deferred gain from a prior year sale of WPD's supply business. WPD recorded a $215 million valuation allowance for the amount of capital losses that, more likely than not, will not be realized. During 2009, PPL recorded a $46 million foreign tax benefit and a related $46 million tax reserve related to losses resulting from restructuring in the U.K. Additionally, PPL recorded a $29 million foreign tax benefit related to the resolution of a tax dispute and foreign currency exchange losses.

[6] During 2011, PPL recorded $17 million in federal and state tax benefits related to the filing of the 2010 federal and state income tax returns. Of this amount, $7 million in tax benefits relate to an additional domestic manufacturing deduction resulting from revised bonus depreciation amounts and $3 million in tax benefits relate to the flow-through impact of Pennsylvania regulated state tax depreciation. During 2009, PPL received consent from the IRS to change its method of accounting for certain expenditures for tax purposes. PPL deducted the resulting IRC Sec. 481 adjustment on its 2008 federal income tax return and recorded a $24 million adjustment to federal and state income tax expense resulting from the reduction in federal income tax benefits related to the domestic manufacturing deduction and certain state tax benefits related to state net operating losses and regulated depreciation.

[7] During 2010, PPL recorded an increase in tax benefits related to domestic manufacturing deductions due to an increase in domestic taxable income resulting from the expiration of generation rate caps in 2010. In December 2010, Congress enacted legislation allowing for 100% bonus depreciation on qualified property. The increased tax depreciation deduction related to bonus depreciation significantly reduced the tax benefits related to domestic manufacturing deductions during 2010 and eliminated the tax benefit in 2011.

[8] Beginning in 2013, provisions within Health Care Reform eliminated the tax deductibility of retiree health care costs to the extent of federal subsidies received by plan sponsors that provide retiree prescription drug benefits equivalent to Medicare Part D Coverage. As a result, PPL recorded deferred income tax expense during 2010. See Note 13 for additional information.

[9] The U.K.'s Finance Act of 2011, enacted in July 2011, included reductions in the U.K. statutory income tax rate. The statutory income tax rate was reduced from 27% to 26% retroactive to April 1, 2011 and will be reduced from 26% to 25 % effective April 1, 2012. As a result, PPL reduced its net deferred tax liabilities and recognized a deferred tax benefit during 2011 related to both tax rate decreases. The U.K.'s Finance Act of 2010, enacted in July 2010, included a reduction in the U.K. statutory income tax rate. Effective April 1, 2011, the statutory income tax rate was reduced from 28% to 27%. As a result, PPL reduced its net deferred tax liabilities and recognized a deferred tax benefit.

[10] During 2011 and 2010, PPL recorded a deferred tax benefit related to investment tax credits on progress expenditures related to hydroelectric plant expansions. See Note 8 for additional information.

[11] During 2011, PPL completed the sale of certain non-core generation facilities. See Note 9 for additional information. Due to changes in state apportionment resulting in the reduction in the future estimated state tax rate, PPL recorded a deferred tax benefit related to its December 31, 2011 state deferred tax liabilities.

[12] Primarily related to a $101 million valuation allowance that was recorded against certain deferred tax assets as a result of the 2011 acquisition of WPD Midlands. See Note 10 for additional information on the acquisition.

[13] A valuation allowance was recorded against certain deferred tax assets as a result of the 2010 acquisition of LKE. See Note 10 for additional information on the acquisition.

[14] Related to the change in foreign net operating loss carryforwards, including the change in foreign currency exchange rates.

[15] The reduction of the U.K. statutory income tax rate resulted in a $35 million reduction in the valuation allowance. See "Reconciliation of Income Tax Expense" below for more information on the impact of the U.K. Finance Act of 2011.

[16] Resulting from the projected revenue increase in connection with the expiration of the Pennsylvania generation rate caps in 2010, the valuation allowance related to state net operating loss carryforwards over the remaining carryforward period was reduced by $72 million (or $0.17 per share, basic and diluted).

[17] Primarily from the projected revenue increase in connection with the expiration of the Pennsylvania generation rate caps in 2010, the valuation allowance related to a portion of state net operating loss carryforwards was reduced by $13 million.

[18] 2010 loss and credit carryforwards associated with the acquisition of LKE. LKE's federal capital loss carryforwards were fully utilized in 2011.

[19] 2010 state net operating loss and state capital loss carryforwards associated with the acquisition of LKE are $1.0 billion and $163 million.

[20] 2011 includes $456 million of foreign capital losses associated with WPD Midlands.

[21] Through an indirect wholly owned subsidiary, PPL acquired WPD Midlands on April 1, 2011. PPL is obligated for the acquired companies' tax liability commencing with tax year 2011. The acquired companies are no longer subject to audit for 2007 and prior years.