Other, Net - Summary of other, net (income) expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other, net (income) expense
Foreign currency exchange transactions	$ 0.3	$ (0.6)	$ 2.5	$ 0.7
Gain on equity investments	(0.1)	(0.2)	(0.4)	(0.2)
Non-service cost component of pension cost	(1.0)	(0.6)	(3.3)	(1.9)
Other	0.3	2.5	(0.2)	2.5
Other, net	$ (0.5)	$ 1.1	$ (1.4)	$ 1.1