Derivative Financial Instruments (Fair Value Of Derivative Instruments In Statement Of Financial Position) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative assets	$ 141.4	$ 114.0
Derivative liabilities	194.0	183.3
Call option | Long-term – Derivative financial instruments
Derivatives, Fair Value [Line Items]
Derivative assets	4.3	9.2
Derivative liabilities	0.0	0.0
Embedded derivative financial instruments | Long-term – Derivative financial instruments
Derivatives, Fair Value [Line Items]
Derivative assets	0.0	0.0
Derivative liabilities	4.3	9.2
Derivatives designated as hedging instruments | Foreign exchange contract
Derivatives, Fair Value [Line Items]
Derivative assets	129.1	92.8
Derivative liabilities	173.0	163.3
Derivatives designated as hedging instruments | Foreign exchange contract | Current – Derivative financial instruments
Derivatives, Fair Value [Line Items]
Derivative assets	94.3	83.8
Derivative liabilities	125.0	127.7
Derivatives designated as hedging instruments | Foreign exchange contract | Long-term – Derivative financial instruments
Derivatives, Fair Value [Line Items]
Derivative assets	34.8	9.0
Derivative liabilities	48.0	35.6
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative assets	8.0	12.0
Derivative liabilities	16.7	10.8
Derivatives not designated as hedging instruments | Foreign exchange contract | Current – Derivative financial instruments
Derivatives, Fair Value [Line Items]
Derivative assets	7.6	11.9
Derivative liabilities	16.3	10.7
Derivatives not designated as hedging instruments | Foreign exchange contract | Long-term – Derivative financial instruments
Derivatives, Fair Value [Line Items]
Derivative assets	0.4	0.1
Derivative liabilities	0.4	0.1
Cash flow hedging | Foreign exchange contract
Derivatives, Fair Value [Line Items]
Gain (loss) recognized in OCI (effective portion)	$ 10.3	$ (75.4)	$ 72.1