Financial Instruments (Foreign Exchange Risk and Its Classification on Balance Sheet) (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Designated as Hedging Instrument
Derivatives, Fair Value
Asset position	$ 3.2	$ 4.4
Liability position	0.8	1.4
Not Designated as Hedging Instrument
Derivatives, Fair Value
Asset position	22.8	18.0
Liability position	9.5	8.3
Potential effect of rights to offset, asset position	(3.9)	(1.7)
Potential effect of rights to offset, liability position	(3.9)	(1.7)
Net derivative, asset position	18.9	16.3
Net derivative, liability position	5.6	6.6
Foreign Exchange Contract | Prepaid expenses and other current assets | Designated as Hedging Instrument
Derivatives, Fair Value
Asset position	0.0	4.3
Foreign Exchange Contract | Prepaid expenses and other current assets | Not Designated as Hedging Instrument
Derivatives, Fair Value
Asset position	19.6	13.6
Foreign Exchange Contract | Accounts payable and accrued expenses | Designated as Hedging Instrument
Derivatives, Fair Value
Liability position	0.0	0.1
Foreign Exchange Contract | Accounts payable and accrued expenses | Not Designated as Hedging Instrument
Derivatives, Fair Value
Liability position	8.7	6.9
Interest Rate Contract | Long-term borrowings | Designated as Hedging Instrument
Derivatives, Fair Value
Asset position	3.2	0.1
Liability position	$ 0.8	$ 1.3