Derivative Financial Instruments - Schedule of Change in Fair Value of Foreign Currency Forward Exchange Contracts Under Hedge Designations (Details) - Designated as Hedging Instrument - Foreign Currency Forward Exchange Contracts - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative [Line Items]
Unrealized gains (losses) at beginning of period, net of tax	$ 8.6	$ (25.9)
(Gains) Losses reclassified to net sales	(1.6)	5.0
Increase in fair value	6.4	2.6
Unrealized gain (losses) at end of period, net of tax	$ 13.4	$ (18.3)