Available-for-Sale Securities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	$ 500				$ 494
Gross unrealized gains	285				239
Gross unrealized losses	2				2
Fair value	783				731
Available-for-Sale Securities Scheduled Maturity Dates of Debt Securities (Details) [Abstract]
Amortized cost - maturity less than 1 year	13
Amortized cost - maturity between 1 and 5 years	82
Amortized cost - maturity between 6 and 10 years	62
Amortized cost - maturity in excess of 10 years	77
Amortized cost total	234
Fair value - maturity less than 1 year	13
Fair value - maturity between 1 and 5 years	85
Fair value - maturity between 6 and 10 years	68
Fair value - maturity in excess of 10 years	83
Fair value total	249
Available-for-Sale Securities Proceeds From and Realized Gains and Losses (Details) [Abstract]
Proceeds from sales of NDT securities	24		34
Gross realized gains	4	[1]	6	[1]
Gross realized losses	2	[1]	1	[1]
Nuclear Decommissioning Trust Funds [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	480				474
Gross unrealized gains	285				239
Gross unrealized losses	1				1
Fair value	764				712
Nuclear Decommissioning Trust Funds [Member] | Cash And Cash Equivalents [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	8				11
Gross unrealized gains
Gross unrealized losses
Fair value	8				11
Nuclear Decommissioning Trust Funds [Member] | United States Large Cap Equity Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	225				222
Gross unrealized gains	232				190
Gross unrealized losses
Fair value	457				412
Nuclear Decommissioning Trust Funds [Member] | United States Mid Small Cap Equity Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	32				30
Gross unrealized gains	36				30
Gross unrealized losses
Fair value	68				60
Nuclear Decommissioning Trust Funds [Member] | United States Treasury Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	86				86
Gross unrealized gains	9				9
Gross unrealized losses
Fair value	95				95
Nuclear Decommissioning Trust Funds [Member] | United States Government Sponsored Agency Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	8				8
Gross unrealized gains	1				1
Gross unrealized losses
Fair value	9				9
Nuclear Decommissioning Trust Funds [Member] | Municipality Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	80				78
Gross unrealized gains	4				5
Gross unrealized losses	1				1
Fair value	83				82
Nuclear Decommissioning Trust Funds [Member] | Investment Grade Corporate Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	37				36
Gross unrealized gains	3				4
Gross unrealized losses
Fair value	40				40
Nuclear Decommissioning Trust Funds [Member] | Other Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	3				3
Gross unrealized gains
Gross unrealized losses
Fair value	3				3
Nuclear Decommissioning Trust Funds [Member] | Receivables Payables Net [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	1
Gross unrealized gains
Gross unrealized losses
Fair value	1
Auction Rate Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	20				20
Gross unrealized gains
Gross unrealized losses	1				1
Fair value	19				19
PPL Energy Supply LLC [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	497				491
Gross unrealized gains	285				239
Gross unrealized losses	2				2
Fair value	780				728
Available-for-Sale Securities Scheduled Maturity Dates of Debt Securities (Details) [Abstract]
Amortized cost - maturity less than 1 year	13
Amortized cost - maturity between 1 and 5 years	82
Amortized cost - maturity between 6 and 10 years	62
Amortized cost - maturity in excess of 10 years	74
Amortized cost total	231
Fair value - maturity less than 1 year	13
Fair value - maturity between 1 and 5 years	85
Fair value - maturity between 6 and 10 years	68
Fair value - maturity in excess of 10 years	80
Fair value total	246
Available-for-Sale Securities Proceeds From and Realized Gains and Losses (Details) [Abstract]
Proceeds from sales of NDT securities	24		34
Gross realized gains	4	[1]	6	[1]
Gross realized losses	2	[1]	1	[1]
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	480				474
Gross unrealized gains	285				239
Gross unrealized losses	1				1
Fair value	764				712
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | Cash And Cash Equivalents [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	8				11
Gross unrealized gains
Gross unrealized losses
Fair value	8				11
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | United States Large Cap Equity Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	225				222
Gross unrealized gains	232				190
Gross unrealized losses
Fair value	457				412
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | United States Mid Small Cap Equity Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	32				30
Gross unrealized gains	36				30
Gross unrealized losses
Fair value	68				60
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | United States Treasury Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	86				86
Gross unrealized gains	9				9
Gross unrealized losses
Fair value	95				95
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | United States Government Sponsored Agency Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	8				8
Gross unrealized gains	1				1
Gross unrealized losses
Fair value	9				9
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | Municipality Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	80				78
Gross unrealized gains	4				5
Gross unrealized losses	1				1
Fair value	83				82
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | Investment Grade Corporate Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	37				36
Gross unrealized gains	3				4
Gross unrealized losses
Fair value	40				40
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | Other Debt Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	3				3
Gross unrealized gains
Gross unrealized losses
Fair value	3				3
PPL Energy Supply LLC [Member] | Nuclear Decommissioning Trust Funds [Member] | Receivables Payables Net [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	1
Gross unrealized gains
Gross unrealized losses
Fair value	1
PPL Energy Supply LLC [Member] | Auction Rate Securities [Member]
Available-for-Sale Securities Balance Sheet (Details) [Abstract]
Amortized cost	17				17
Gross unrealized gains
Gross unrealized losses	1				1
Fair value	$ 16				$ 16

[1] Excludes the impact of other-than-temporary impairment charges recognized on the Statements of Income.