Other, Net - Summary of other, net (income) expense - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Foreign currency exchange transactions	$ 2.2	$ 2.4	$ (2.1)
(Gain) loss on equity investments	(0.2)	(0.1)	0.1
Other	1.7	(3.4)	(3.6)
Other, net	$ 3.7	$ (1.1)	$ (5.6)