Income and Other Taxes (Credit Carryforwards and Valuation Allowances and Reserves) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Valuation Allowances and Reserves (Details) [Roll Forward]
Permanently reinvested cumulative undistributed foreign earnings	$ 2,000,000,000		$ 1,200,000,000
Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	724,000,000		464,000,000		312,000,000
Additions charged to income	18,000,000		190,000,000		221,000,000
Additions charged to other accounts	10,000,000		112,000,000	[1]	6,000,000
Deductions	46,000,000	[2]	42,000,000	[3]	75,000,000	[4]
Balance at end of period	706,000,000		724,000,000		464,000,000
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 related to expiration of generation rate caps					72,000,000
Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	233,000,000
Expiration	2025-2032
Alternative Minimum Tax Credit [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	20,000,000
Expiration	Indefinite
Foreign Tax Credit [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	1,000,000
Expiration	2017-2022
Other [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	30,000,000
Expiration	2016-2032
Other [Member] | State [Member]
Credit carryforwards
Credit carryforwards, amount	4,000,000
Expiration	2022
PPL Energy Supply LLC [Member] | Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	72,000,000		408,000,000		255,000,000
Additions charged to income	2,000,000		22,000,000		205,000,000
Additions charged to other accounts
Deductions			358,000,000	[5]	52,000,000	[6]
Balance at end of period	74,000,000		72,000,000		408,000,000
Valuation allowance reduction related to state net operating loss carryforwards related to expiration of generation rate caps					52,000,000
PPL Energy Supply LLC [Member] | Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	108,000,000
Expiration	2031-2032
PPL Energy Supply LLC [Member] | Other [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	5,000,000
Expiration	2031-2032
LG And E And KU Energy LLC [Member] | Valuation Allowance Of Deferred Tax Assets [Member]
Valuation Allowances and Reserves (Details) [Roll Forward]
Balance at beginning of period	5,000,000		6,000,000		7,000,000
Additions charged to other accounts					6,000,000	[7]
Deductions			1,000,000	[8]	7,000,000	[9]
Balance at end of period	5,000,000		5,000,000		6,000,000
LG And E And KU Energy LLC [Member] | Investment Tax Credit [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	125,000,000
Expiration	2025-2028
LG And E And KU Energy LLC [Member] | Alternative Minimum Tax Credit [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	20,000,000
Expiration	Indefinite
LG And E And KU Energy LLC [Member] | Other [Member] | Federal [Member]
Credit carryforwards
Credit carryforwards, amount	25,000,000
Expiration	2016-2032
LG And E And KU Energy LLC [Member] | Other [Member] | State [Member]
Credit carryforwards
Credit carryforwards, amount	$ 4,000,000
Expiration	2022

[1] 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.

[2] The reduction of the U.K. statutory income tax rate resulted in a reduction in deferred tax assets and the corresponding valuation allowances. See "Reconciliation of Income Tax Expense" below for more information on the impact of the U.K. Finance Act of 2012.

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

[4] 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.

[5] During 2011, PPL Energy Supply distributed its membership interest in PPL Global to PPL Energy Funding. See Note 9 for additional information.

[6] 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 $52 million.

[7] A valuation allowance was recorded against deferred tax assets for state capital loss carryforwards.

[8] Primarily related to the expiration of state capital loss carryforwards.

[9] Related to release of a valuation allowance associated with federal capital loss carryforwards due to the LKE acquisition by PPL.