Commitments and Contingencies (Litigation) (Narrative) (Details) - Pending Litigation [Member] $ in Millions	1 Months Ended			6 Months Ended	12 Months Ended
	Aug. 31, 2014 USD ($)	Jun. 30, 2013 USD ($)	Oct. 31, 2012 USD ($) mi	Jun. 30, 2015 USD ($)	Dec. 31, 2011
PPL [Member]
Loss Contingencies [Line Items]
Contract price, pending litigation (in dollars)			$ 206
Construction contract, number of miles of transmission line | mi			100
Claims sought, pending litigation (in dollars)				$ 40
Sunlight Entities [Member]
Loss Contingencies [Line Items]
Claims sought, pending litigation (in dollars)		$ 60
Number of public solar projects					3
Number of arbitration proceedings					3
Arbitration award, pending litigation (in dollars)	$ 68