Derivative And Hedging Instruments (Schedule Of Effect Of Derivative Instruments Not Designated As Hedging Instruments In Consolidated Statements Of Income) (Details) (Interest Expense [Member], Interest Rate Caps [Member], Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest Expense [Member] | Interest Rate Caps [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Loss) / Gain Recognized in Income on Derivatives	$ (0.1)	$ (0.1)	$ (0.1)