Derivative Instruments and Hedging Activities (Commodity Volumetric Activity) (Details)	Dec. 31, 2011 MW
Commodity Volumetric Activity - Sales of Baseload Generation (Numeric) [Abstract]
Baseload Generation Fleet Generating Capacity	7,252
Commodity Volumetric Activity - Optimization of Intermediate and Peaking Generation (Numeric) [Abstract]
Intermediate and peaking generation fleet capacity (in MW)	3,256
2012 [Member] | GWh [Member]
Expected Sales, in GWh, of Baseload Generation [Abstract]
Expected sales of baseload generation (in GWh)	53,737
2012 [Member] | Percent Unit [Member]
Percentage Of Expected Baseload Generation Sales [Abstract]
Derivative sales, as percentage of expected baseload generation	85.00%	[1]
Total power sales, as percentage of expected baseload generation	93.00%	[2]
Coal fuel purchases, as percentage of expected baseload generation	98.00%	[3]
Nuclear fuel purchases, as percentage of expected baseload generation	100.00%	[3]
2013 [Member] | GWh [Member]
Expected Sales, in GWh, of Baseload Generation [Abstract]
Expected sales of baseload generation (in GWh)	53,136
2013 [Member] | Percent Unit [Member]
Percentage Of Expected Baseload Generation Sales [Abstract]
Derivative sales, as percentage of expected baseload generation	63.00%	[1]
Total power sales, as percentage of expected baseload generation	71.00%	[2]
Coal fuel purchases, as percentage of expected baseload generation	89.00%	[3]
Nuclear fuel purchases, as percentage of expected baseload generation	100.00%	[3]
2014 [Member] | GWh [Member]
Expected Sales, in GWh, of Baseload Generation [Abstract]
Expected sales of baseload generation (in GWh)	53,502
2014 [Member] | Percent Unit [Member]
Percentage Of Expected Baseload Generation Sales [Abstract]
Derivative sales, as percentage of expected baseload generation	4.00%	[1],[4]
Total power sales, as percentage of expected baseload generation	10.00%	[2]
Coal fuel purchases, as percentage of expected baseload generation	62.00%	[3]
Nuclear fuel purchases, as percentage of expected baseload generation	100.00%	[3]
Future Years [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Volumes for sales contracts that deliver in future years	1,541
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Power basis positions (in GWh)	(677)
Future Years [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Volumes for sales contracts that deliver in future years	7.2
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Gas basis positions (in Bcf)	(5.1)
Future Years [Member] | MW-months [Member]
Capacity Positions [Abstract]
Capacity positions that deliver in future periods (in MW-months)	989
Capacity [Member] | 2012 [Member] | MW-months [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(7,797)
Capacity [Member] | 2013 [Member] | MW-months [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(3,108)
Capacity [Member] | 2014 [Member] | MW-months [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(2,578)	[5]
FTRs [Member] | 2012 [Member] | GWh [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
FTRs positions (in GWh)	16,562
FTRs [Member] | 2013 [Member] | GWh [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
FTRs positions (in GWh)	0
FTRs [Member] | 2014 [Member] | GWh [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
FTRs positions (in GWh)	0
Power Basis Positions [Member] | 2012 [Member] | GWh [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Power basis positions (in GWh)	(18,035)
Power Basis Positions [Member] | 2013 [Member] | GWh [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Power basis positions (in GWh)	(8,343)
Power Basis Positions [Member] | 2014 [Member] | GWh [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Power basis positions (in GWh)	(2,628)	[6]
Gas Basis Positions [Member] | 2012 [Member] | Bcf [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Gas basis positions (in Bcf)	11.0
Gas Basis Positions [Member] | 2013 [Member] | Bcf [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Gas basis positions (in Bcf)	(5.2)
Gas Basis Positions [Member] | 2014 [Member] | Bcf [Member]
Volumes of Derivative FTR and basis (sales)/purchase contracts [Abstract]
Gas basis positions (in Bcf)	(0.9)	[6]
Energy Sales Contracts [Member] | 2012 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(16,235)	[7]
Energy Sales Contracts [Member] | 2013 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(6,524)	[7]
Energy Sales Contracts [Member] | 2014 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(3,681)	[7]
Related Energy Supply Contracts [Member] | Energy Purchases [Member] | 2012 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	10,658	[7]
Related Energy Supply Contracts [Member] | Energy Purchases [Member] | 2013 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	1,359	[7]
Related Energy Supply Contracts [Member] | Energy Purchases [Member] | 2014 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	136	[7]
Related Energy Supply Contracts [Member] | Volumetric Hedges [Member] | 2012 [Member] | GWh [Member]
Volumes of (Sales)/Purchase Contracts, Excluding FTRs, Renewable Energy Credits, Basis and Capacity Contracts [Abstract]
Volumetric hedge volumes (in units)	254	[7],[8]
Related Energy Supply Contracts [Member] | Volumetric Hedges [Member] | 2013 [Member] | GWh [Member]
Volumes of (Sales)/Purchase Contracts, Excluding FTRs, Renewable Energy Credits, Basis and Capacity Contracts [Abstract]
Volumetric hedge volumes (in units)	128	[7],[8]
Related Energy Supply Contracts [Member] | Volumetric Hedges [Member] | 2014 [Member] | GWh [Member]
Volumes of (Sales)/Purchase Contracts, Excluding FTRs, Renewable Energy Credits, Basis and Capacity Contracts [Abstract]
Volumetric hedge volumes (in units)	93	[7],[8]
Related Energy Supply Contracts [Member] | Generation Supply [Member] | 2012 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	5,389	[7]
Related Energy Supply Contracts [Member] | Generation Supply [Member] | 2013 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	4,462	[7]
Related Energy Supply Contracts [Member] | Generation Supply [Member] | 2014 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	3,259	[7]
Retail Gas Sales Contracts [Member] | 2012 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(13.5)
Retail Gas Sales Contracts [Member] | 2013 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(2.6)
Retail Gas Sales Contracts [Member] | 2014 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(0.7)
Retail Gas Purchase Contracts [Member] | 2012 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	13.2
Retail Gas Purchase Contracts [Member] | 2013 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	2.5
Retail Gas Purchase Contracts [Member] | 2014 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	0.7
Net Power Sales [Member] | 2012 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(2,860)
Net Power Sales [Member] | 2013 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(1,224)
Net Power Sales [Member] | 2014 [Member] | GWh [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	(408)	[9]
Net Fuel Purchases [Member] | 2012 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	27.1	[10]
Net Fuel Purchases [Member] | 2013 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	8.1	[10]
Net Fuel Purchases [Member] | 2014 [Member] | Bcf [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	2.5	[10],[9]
Oil Swap [Member] | 2012 [Member] | Thousand of Barrels [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	591
Oil Swap [Member] | 2013 [Member] | Thousand of Barrels [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	540
Oil Swap [Member] | 2014 [Member] | Thousand of Barrels [Member]
Notional amounts included under applicable contracts [Abstract]
Notional amount (in units)	240

[1] Excludes non-derivative contracts and contracts that qualify for NPNS. Volumes for option contracts factor in the probability of an option being exercised and may be less than the notional amount of the option.

[2] Amount represents derivative (including contracts that qualify for NPNS) and non-derivative contracts. Volumes for option contracts factor in the probability of an option being exercised and may be less than the notional amount of the option. Percentages are based on fixed-price contracts only.

[3] Coal and nuclear contracts receive accrual accounting treatment, as they are not derivative contracts. Percentages are based on both fixed- and variable-priced contracts.

[4] Volumes for derivative sales contracts that deliver in future periods total 1,541 GWh and 7.2 Bcf.

[5] Volumes that deliver in future periods are 989 MW-months.

[6] Net volumes that deliver in future periods are (677) GWh and (5.1) Bcf.

[7] Includes NPNS and contracts that are not derivatives, which receive accrual accounting.

[8] PPL Energy Supply uses power and gas options, swaps and futures to hedge the volumetric risk associated with full-requirement sales contracts since the demand for power varies hourly. Volumes for option contracts factor in the probability of an option being exercised and may be less than the notional amount of the option.

[9] Volumes for derivative contracts used in support of these strategies that deliver in future periods are insignificant.

[10] Included in these volumes are non-options and exercised option contracts that converted to non-option derivative contracts. Volumes associated with option contracts are not significant.