Derivative Instruments And Hedging Activities (Fair Value Of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Derivatives assets	$ 8.4	$ 12.6
Derivatives liabilities	4.6	6.8
Derivatives Designated As Accounting Hedges [Member]
Derivative [Line Items]
Derivatives assets	8.2	11.5
Derivatives liabilities	3.6	4.5
Derivatives Designated As Accounting Hedges [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Derivatives assets	8.2	11.5
Derivatives liabilities	3.6	4.5
Derivatives Not Designated As Accounting Hedges [Member]
Derivative [Line Items]
Derivatives assets	0.2	1.1
Derivatives liabilities	$ 1.0	$ 2.3