Pension and Post-retirement and Other Benefit Plans - Net Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1	$ 233.0
Fair value of plan assets at December 31	261.5	$ 233.0
Amounts recognized in the Consolidated Balance Sheets at December 31
Accrued pension and other post-retirement benefits, less current portion	(85.9)	(86.1)
Pensions
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at January 1	317.4	316.3
Service cost	1.7	1.4	$ 1.5
Interest cost	10.7	11.4	13.7
Actuarial (gain) loss	23.9	11.4
Plan participants' contributions	0.1	0.2
Business combinations	0.0	2.1
Benefits paid	(13.8)	(23.2)
Currency translation adjustments	4.9	(2.2)
Projected benefit obligation at December 31	344.9	317.4	316.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1	233.0	227.3
Company contributions	11.1	10.3
Actual return (loss) on plan assets	29.8	18.8
Plan participants' contributions	0.1	0.2
Benefits paid	13.8	23.2
Currency translation adjustments	1.3	(0.4)
Fair value of plan assets at December 31	261.5	233.0	227.3
Funded status of the plans (liability) at December 31	(83.4)	(84.4)
Amounts recognized in the Consolidated Balance Sheets at December 31
Other current liabilities	(0.9)	(1.3)
Accrued pension and other post-retirement benefits, less current portion	(82.5)	(83.1)
Net amount recognized	(83.4)	(84.4)
Other post-retirement benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at January 1	3.3	3.2
Service cost	0.0	0.0	0.0
Interest cost	0.1	0.1	0.2
Actuarial (gain) loss	0.3	0.4
Benefits paid	(0.2)	(0.4)
Projected benefit obligation at December 31	3.5	3.3	$ 3.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Company contributions	0.2	0.4
Benefits paid	0.2	0.4
Funded status of the plans (liability) at December 31	(3.5)	(3.3)
Amounts recognized in the Consolidated Balance Sheets at December 31
Other current liabilities	(0.3)	(0.2)
Accrued pension and other post-retirement benefits, less current portion	(3.2)	(3.1)
Net amount recognized	$ (3.5)	$ (3.3)