Derivative Instruments and Hedging Activities (Commodity Volumes) (Details)	Sep. 30, 2014 MWh
Sales Contracts [Member] | Power [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	12,324,114	[1],[2]
Sales Contracts [Member] | Power [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	32,192,825	[1]
Sales Contracts [Member] | Power [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,488,139	[1]
Sales Contracts [Member] | Capacity [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	4,070	[1],[2]
Sales Contracts [Member] | Capacity [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,554	[1]
Sales Contracts [Member] | Oil [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	141,236	[1],[2]
Purchase Contracts [Member] | Power [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,457,755	[1]
Purchase Contracts [Member] | Capacity [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	501	[1]
Purchase Contracts [Member] | Capacity [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	9	[1]
Purchase Contracts [Member] | Gas [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	46,661,053	[1],[2]
Purchase Contracts [Member] | Gas [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	59,985,428	[1]
Purchase Contracts [Member] | Gas [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	34,896,181	[1]
Purchase Contracts [Member] | Gas [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	6,831,035	[1]
Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,457	[1],[2]
Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	3,051	[1]
Purchase Contracts [Member] | Oil [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	374,062	[1]
Purchase Contracts [Member] | Oil [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	328,837	[1]
Purchase Contracts [Member] | Oil [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	274,872	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Power [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	12,324,114	[1],[2]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Power [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	32,192,825	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Power [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,488,139	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Capacity [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	4,070	[1],[2]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Capacity [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,554	[1]
PPL Energy Supply LLC [Member] | Sales Contracts [Member] | Oil [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	141,236	[1],[2]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Power [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	5,457,755	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Capacity [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	501	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Capacity [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	9	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	46,661,053	[1],[2]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	59,985,428	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	34,896,181	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Gas [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	6,831,035	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2014 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	1,457	[1],[2]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Financial Transmission Rights [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	3,051	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Oil [Member] | 2015 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	374,062	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Oil [Member] | 2016 [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	328,837	[1]
PPL Energy Supply LLC [Member] | Purchase Contracts [Member] | Oil [Member] | Thereafter [Member]
Commodity Volumetric Activity [Line Items]
Notional amount (in units)	274,872	[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.