Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Deferred gains to be reclassified in next 12 months			$ 0.4
Foreign Exchange Contract | Designated as Hedging Instrument
Derivative [Line Items]
Notional amount					$ 78.7
Maximum duration (in months)			6 months
Fair value - net asset					4.2
Amount of net losses recognized in OCI	$ (0.1)	$ (3.4)	$ (0.7)	$ (3.4)
Foreign Exchange Contract | Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	1,495.1		$ 1,495.1		$ 1,309.1
Maximum duration (in months)			3 months		3 months
Fair value - net asset	10.9		$ 10.9		$ 6.7
Interest Expense | Interest Rate Contract | Designated as Hedging Instrument
Derivative [Line Items]
Ineffectiveness reported as component of interest expense	$ (0.2)		$ (1.4)