Pension Plans and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined contribution retirement plan
Percentage that the employer contributes of employee contributions under 401(k) plan	100.00%
Maximum percentage of employee compensation match by employer to defined contribution plan	6.00%
Costs related to defined contribution retirement plan	$ 2.8	$ 2.7
Foreign Plan [Member]
Net Periodic Benefit Cost
Service cost	2.4	2.0
Interest cost	1.3	1.0
Expected return on plan assets	(0.3)	(0.2)
Amortization of prior service credit	0.0	0.0
Net periodic benefit cost (income)	3.4	2.8
Domestic Plan [Member]
Net Periodic Benefit Cost
Service cost	4.8	4.3
Interest cost	10.3	10.5
Expected return on plan assets	(14.5)	(14.4)
Amortization of prior service credit	(0.2)	(0.1)
Net periodic benefit cost (income)	$ 0.4	$ 0.3