Commitments and Contingencies (Litigation) (Narrative) (Details) $ in Millions	1 Months Ended				3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2013 USD ($)	Oct. 31, 2012 USD ($) mi	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2011
PPL [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Contract price, litigation (in dollars)				$ 206.0
Construction contract, number of miles of transmission line | mi				100
Claims sought, litigation (in dollars)		$ 40.0
PPL [Member] | Settled Litigation [Member] | Other Expense [Member] | Electrical Transmission [Member]
Loss Contingencies [Line Items]
Court mandated mediation settlement, charge (in dollars)					$ 12.2	$ 12.2
Sunlight Entities [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Claims sought, litigation (in dollars)			$ 60.0
Number of public solar projects							3
Number of arbitration proceedings							3
Arbitration award, litigation (in dollars)	$ 68.0