Derivative Instruments and Hedging Activities (Commodity Volumes) (Details)	Sep. 30, 2013 MWh
Sales Contracts [Member] | Power [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	9,950,950	[1],[2]
Sales Contracts [Member] | Power [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	28,280,182	[1]
Sales Contracts [Member] | Power [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	4,110,530	[1]
Sales Contracts [Member] | Capacity [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,114	[1],[2]
Sales Contracts [Member] | Capacity [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	14,418	[1]
Sales Contracts [Member] | Capacity [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	309	[1]
Sales Contracts [Member] | Gas [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	3,852,725	[1]
Sales Contracts [Member] | Coal [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	30,000	[1]
Sales Contracts [Member] | Oil [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	15,335	[1],[2]
Purchase Contracts [Member] | Power [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	10,991,752	[1]
Purchase Contracts [Member] | Capacity [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,990	[1]
Purchase Contracts [Member] | Gas [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	12,653,279	[1],[2]
Purchase Contracts [Member] | Gas [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	18,794,545	[1]
Purchase Contracts [Member] | Gas [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,320,453	[1]
Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,056	[1],[2]
Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	8,724	[1]
Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,465	[1]
Purchase Contracts [Member] | Oil [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	300,000	[1]
Purchase Contracts [Member] | Oil [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	384,334	[1]
Purchase Contracts [Member] | Oil [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	371,466	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Power [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	9,950,950	[1],[2]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Power [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	28,280,182	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Power [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	4,110,530	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Capacity [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,114	[1],[2]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Capacity [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	14,418	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Capacity [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	309	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Gas [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	3,852,725	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Coal [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	30,000	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Oil [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	15,335	[1],[2]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Power [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	10,991,752	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Capacity [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,990	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	12,653,279	[1],[2]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	18,794,545	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,320,453	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2013 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,056	[1],[2]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	8,724	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,465	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Oil [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	300,000	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Oil [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	384,334	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Oil [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	371,466	[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.