Derivative Instruments and Hedging Activities (Commodity Volumes) (Details)	Mar. 31, 2013 MWh
Power [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(27,422,031)	[1],[2]
Power [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(22,385,959)	[1]
Power [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(490,995)	[1]
Power [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,415,573	[1]
Capacity [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(11,655)	[1],[2]
Capacity [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(6,630)	[1]
Capacity [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(13)	[1]
Capacity [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	525	[1]
Gas [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(5,339,243)	[1],[2]
Gas [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(25,106,607)	[1]
Gas [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(4,091,856)	[1]
Gas [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(3,678,883)	[1]
Coal [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(186,000)	[1],[2]
Coal [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	186,000	[1]
Coal [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)
Coal [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)
Financial Transmission Rights [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	14,224	[1],[2]
Financial Transmission Rights [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,063	[1]
Financial Transmission Rights [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,465	[1]
Financial Transmission Rights [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)
Oil [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	46,118	[1],[2]
Oil [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	240,000	[1]
Oil [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	300,000	[1]
Oil [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	240,000	[1]
PPL Energy Supply LLC [Member] | Power [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(27,422,031)	[1],[2]
PPL Energy Supply LLC [Member] | Power [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(22,385,959)	[1]
PPL Energy Supply LLC [Member] | Power [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(490,995)	[1]
PPL Energy Supply LLC [Member] | Power [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,415,573	[1]
PPL Energy Supply LLC [Member] | Capacity [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(11,655)	[1],[2]
PPL Energy Supply LLC [Member] | Capacity [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(6,630)	[1]
PPL Energy Supply LLC [Member] | Capacity [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(13)	[1]
PPL Energy Supply LLC [Member] | Capacity [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	525	[1]
PPL Energy Supply LLC [Member] | Gas [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(5,339,243)	[1],[2]
PPL Energy Supply LLC [Member] | Gas [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(25,106,607)	[1]
PPL Energy Supply LLC [Member] | Gas [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(4,091,856)	[1]
PPL Energy Supply LLC [Member] | Gas [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(3,678,883)	[1]
PPL Energy Supply LLC [Member] | Coal [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	(186,000)	[1],[2]
PPL Energy Supply LLC [Member] | Coal [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	186,000	[1]
PPL Energy Supply LLC [Member] | Coal [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)
PPL Energy Supply LLC [Member] | Coal [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)
PPL Energy Supply LLC [Member] | Financial Transmission Rights [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	14,224	[1],[2]
PPL Energy Supply LLC [Member] | Financial Transmission Rights [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,063	[1]
PPL Energy Supply LLC [Member] | Financial Transmission Rights [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,465	[1]
PPL Energy Supply LLC [Member] | Financial Transmission Rights [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)
PPL Energy Supply LLC [Member] | Oil [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	46,118	[1],[2]
PPL Energy Supply LLC [Member] | Oil [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	240,000	[1]
PPL Energy Supply LLC [Member] | Oil [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	300,000	[1]
PPL Energy Supply LLC [Member] | Oil [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	240,000	[1]

[1] 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] Represents balance of the current year.