Derivative Financial Instruments - Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosures [Line Items]
(Gain) loss on non-derivative instruments, net	$ 11.8	$ 4.3	$ (5.5)
Other Nonoperating Income (Expense) [Member] | Foreign Exchange Contract [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
(Gain) loss on non-derivative instruments, net	11.2	4.3	(5.6)
Interest Expense [Member] | Interest Rate Cap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
(Gain) loss on non-derivative instruments, net	$ 0.6	$ 0.0	$ 0.1