Other Charges, Net - Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Charges, Net
Acquisition-related expenses (income), net	$ 4.5	$ 9.0	$ (7.2)
Professional fees incurred in connection with internal investigation	0.2		0.4
Pension settlement charge			10.2
Information technology transformation costs	4.2	6.2	8.9
Restructuring charges	10.6	9.8	8.1
Long-lived asset impairments	0.2	0.8	4.6
Other charges, net	$ 19.7	$ 25.8	$ 25.0