Derivatives and Hedging Activities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value of Derivative Instruments
Derivative Asset, Fair Value, Net, Total	$ 61.5	$ 20.6
Derivative Liability, Fair Value, Net, Total	(5.2)	(3.6)
Designated as Hedging Instrument [Member] | Foreign currency forward contracts [Member]
Fair Value of Derivative Instruments
Derivative Asset, Fair Value, Net, Total		0.5
Derivative Liability, Fair Value, Net, Total		(0.6)
Designated as Hedging Instrument [Member] | Interest Rate Swaps [Member]
Fair Value of Derivative Instruments
Derivative Asset, Fair Value, Net, Total	1.8	2.1
Derivative Liability, Fair Value, Net, Total	(0.2)
Not Designated as Hedging Instrument [Member] | Foreign currency forward contracts [Member]
Fair Value of Derivative Instruments
Derivative Asset, Fair Value, Net, Total	59.7	18.0
Derivative Liability, Fair Value, Net, Total	$ (5.0)	$ (3.0)