Pensions - Summary of Components of Net Periodic Pension Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Interest cost	1.7	1.6	3.4	3.2
Amortization of actuarial loss	0.6	0.7	1.2	1.5
Amortization of prior service cost	0.0	0.0	0.0	0.0
Expected return on plan assets	(2.2)	(2.2)	(4.4)	(4.4)
Net periodic pension expense (benefit)	0.1	0.1	0.2	0.3
Non-U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.1	0.1
Interest cost	0.4	0.4	0.7	0.7
Amortization of actuarial loss	0.1	0.1	0.3	0.3
Amortization of prior service cost	0.1	0.0	0.1	0.0
Expected return on plan assets	(0.5)	(0.6)	(1.0)	(1.2)
Net periodic pension expense (benefit)	$ 0.1	$ (0.1)	$ 0.2	$ (0.1)