Derivative Financial Instruments (Fair Value Of Derivative Instruments In Balance Sheets) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value
Derivative assets	$ 177.0	$ 173.2
Derivative liabilities	173.3	137.1
Long-term - Derivative financial instruments - Synthetic Bonds - Call Option Premium | Long-Term - Derivative Financial Instruments
Derivatives, Fair Value
Derivative assets	66.4	62.2
Long-term - Derivative financial instruments - Synthetic Bonds - Embedded Derivatives | Long-Term - Derivative Financial Instruments
Derivatives, Fair Value
Derivative liabilities	66.4	62.2
Derivatives Designated As Hedging Instruments | Foreign exchange contracts
Derivatives, Fair Value
Derivative assets	94.6	93.6
Derivative liabilities	93.4	52.7
Derivatives Designated As Hedging Instruments | Foreign exchange contracts | Current - Derivative Financial Instruments
Derivatives, Fair Value
Derivative assets	81.0	65.6
Derivative liabilities	78.6	51.0
Derivatives Designated As Hedging Instruments | Foreign exchange contracts | Long-Term - Derivative Financial Instruments
Derivatives, Fair Value
Derivative assets	13.6	28.0
Derivative liabilities	14.8	1.7
Derivatives Not Designated As Hedging Instruments | Foreign exchange contracts
Derivatives, Fair Value
Derivative assets	16.0	17.4
Derivative liabilities	13.5	22.2
Derivatives Not Designated As Hedging Instruments | Foreign exchange contracts | Current - Derivative Financial Instruments
Derivatives, Fair Value
Derivative assets	16.0	12.7
Derivative liabilities	$ 13.5	18.0
Derivatives Not Designated As Hedging Instruments | Foreign exchange contracts | Long-Term - Derivative Financial Instruments
Derivatives, Fair Value
Derivative assets		4.7
Derivative liabilities		$ 4.2