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
	Mar. 31, 2014	Mar. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ 3.2	$ 9.1
Foreign Currency Forward Contracts [Member] | Foreign Exchange Gain [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Income on Derivative	$ 3.2	$ 9.1