Hedging Transaction and Derivative Instruments - Fair Value of Derivatives Qualifying as Hedging Instrument (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized net gains (losses) arising during period	$ 3.4	$ (2.5)	$ (1.4)
Designated as Hedging Instrument | Cash Flow Hedging | Other expense (income), net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives	0.5	1.0	0.0
Foreign Currency Economic Hedge | Not Designated as Hedging Instrument | Not Designated as Hedging Instrument, Economic Hedge [Member] | Other expense (income), net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivatives	0.3	2.0	$ (0.3)
Foreign Exchange Forward and Interest Rate Swap [Member] | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized net gains (losses) arising during period	$ 0.5	$ 3.2