Derivative Instruments Derivative Instruments Affecting the Consolidated Statements of Income (Details) (Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ 5.5	$ (14.1)	$ 8.7	$ (5.0)
Foreign Currency Forward Contracts [Member] | Foreign Exchange Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ 5.5	$ (14.1)	$ 8.7	$ (5.0)