Pension, Post-Retirement and Post-Employment Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net periodic benefit expense:
Net periodic (benefit) cost	$ 1.0	$ 0.1	$ 11.5
Pension Plan and SERP | Domestic
Net periodic benefit expense:
Service cost	0.0	0.0	0.0
Interest cost on the projected benefit obligation	8.7	8.1	8.8
Expected return on plan assets	(9.6)	(10.4)	(10.1)
Amortization of prior service cost	0.0	0.0	0.0
Amortization of actuarial net loss	0.0	0.0	0.0
Plan curtailment	0.0	0.1	0.0
Plan settlement	0.0	0.2	0.0
Net periodic (benefit) cost	(0.9)	(2.0)	(1.3)
Pension Plan and SERP | Foreign
Net periodic benefit expense:
Service cost	0.7	1.2	1.6
Interest cost on the projected benefit obligation	0.3	0.3	1.4
Expected return on plan assets	(0.1)	(0.1)	(1.3)
Amortization of prior service cost	0.0	0.0	0.1
Amortization of actuarial net loss	0.1	0.0	0.1
Plan curtailment	0.0	0.0	0.3
Plan settlement	0.2	0.1	10.1
Net periodic (benefit) cost	1.2	1.5	12.3
Post-retirement Medical Benefits | Domestic
Net periodic benefit expense:
Service cost	0.0	0.0	0.0
Interest cost on the projected benefit obligation	0.4	0.4	0.4
Net periodic (benefit) cost	0.4	0.4	0.4
Post-retirement Medical Benefits | Foreign
Net periodic benefit expense:
Service cost	0.1	0.1	0.0
Interest cost on the projected benefit obligation	0.1	0.1	0.1
Net periodic (benefit) cost	$ 0.3	$ 0.2	$ 0.1