Derivative Instruments (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss)
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ 2.4	$ 3.9	$ 7.9
Derivatives designated as hedging instruments | Interest-rate swap
Derivative Instruments, Gain (Loss)
Derivative Instruments, Gain (Loss) Recognized in Income, Net	3.2	4.7	7.2
Not Designated as Hedging Instrument [Member] | Forward exchange contracts
Derivative Instruments, Gain (Loss)
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ (0.8)	$ (0.8)	$ 0.7