Fair Value Measurements and Credit Concentration (Nonrecurring Fair Value Measurements) (Details) (Nonrecurring [Member], Kerr Dam Project [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Nonrecurring Fair Value Measurements [Abstract]
Loss	$ 18	[1]
Amount to be included in the Kerr Dam conveyance price	18
Carrying Amount [Member]
Nonrecurring Fair Value Measurements [Abstract]
Nonrecurring measurement asset value	47	[2]
Level 3 [Member]
Nonrecurring Fair Value Measurements [Abstract]
Nonrecurring measurement asset value	29
PPL Energy Supply LLC [Member]
Nonrecurring Fair Value Measurements [Abstract]
Loss	18	[1]
Amount to be included in the Kerr Dam conveyance price	18
PPL Energy Supply LLC [Member] | Carrying Amount [Member]
Nonrecurring Fair Value Measurements [Abstract]
Nonrecurring measurement asset value	47	[2]
PPL Energy Supply LLC [Member] | Level 3 [Member]
Nonrecurring Fair Value Measurements [Abstract]
Nonrecurring measurement asset value	$ 29

[1] The loss on the Kerr Dam Project was recorded in the Supply segment and included in "Other operation and maintenance" on PPL's and PPL Energy Supply's Statement of Income.  

[2] Represents carrying value before fair value measurement.