Employee Benefit Plans - Reconciliation of the Changes in Benefit Obligation, the Changes in Plan Assets, and the Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in Plan Assets
Fair value of plan assets, beginning of year	$ 163.8
Fair value of plan assets, end of year	176.7	$ 163.8
Weighted-Average Assumptions
Short term portion of pension obligation	0.7	0.7
Short term portion of other benefit obligation	1.2	1.0
Pension Plans
Change in Benefit Obligation
Benefit obligation, beginning of year	203.9	177.2
Service cost	0.0	0.2	$ 0.4
Interest cost	5.4	8.3	6.5
Participant contributions	0.0	0.0
Plan combinations	0.0	55.6
Actuarial loss	7.7	4.1
Currency translation adjustment	13.8	(29.3)
Benefits paid	(14.0)	(12.2)
Benefit obligation, end of year	216.8	203.9	177.2
Change in Plan Assets
Fair value of plan assets, beginning of year	163.8	147.9
Actual return on plan assets	9.2	14.1
Employer contributions	5.4	6.1
Participant contributions	0.0	0.0
Plan combinations	0.0	34.1
Currency translation adjustment	12.3	(26.2)
Benefits paid	(14.0)	(12.2)
Fair value of plan assets, end of year	176.7	163.8	147.9
Funded status	$ (40.1)	$ (40.1)
Weighted-Average Assumptions
Discount rate (as a percent)	2.80%	3.10%
Postretirement Health and Other Plans
Change in Benefit Obligation
Benefit obligation, beginning of year	$ 9.0	$ 3.2
Service cost	0.0	0.0	0.0
Interest cost	0.3	0.4	0.1
Participant contributions	0.6	0.4
Plan combinations	0.0	6.8
Actuarial loss	1.7	0.0
Currency translation adjustment	0.1	0.0
Benefits paid	(1.6)	(1.8)
Benefit obligation, end of year	10.1	9.0	3.2
Change in Plan Assets
Fair value of plan assets, beginning of year	0.0	0.0
Actual return on plan assets	0.0	0.0
Employer contributions	1.0	1.4
Participant contributions	0.6	0.4
Plan combinations	0.0	0.0
Currency translation adjustment	0.0	0.0
Benefits paid	(1.6)	(1.8)
Fair value of plan assets, end of year	0.0	0.0	$ 0.0
Funded status	$ (10.1)	$ (9.0)
Weighted-Average Assumptions
Discount rate (as a percent)	3.20%	3.50%
Rate of compensation increase (as a percent)	1.50%	1.50%