Pensions - Summary of Components of Net Periodic Pension Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Interest cost	1.2	1.5	3.6	4.3
Amortization of actuarial loss	1.0	0.8	2.9	2.4
Amortization of prior service cost	0.0	0.0	0.0	0.0
Expected return on plan assets	(2.4)	(2.3)	(7.2)	(6.9)
Net periodic pension benefit	(0.2)	0.0	(0.7)	(0.2)
Non-U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.0	0.0	0.1	0.1
Interest cost	0.2	0.2	0.5	0.7
Amortization of actuarial loss	0.2	0.2	0.6	0.4
Amortization of prior service cost	0.1	0.0	0.2	0.1
Expected return on plan assets	(0.5)	(0.5)	(1.5)	(1.4)
Net periodic pension benefit	$ 0.0	$ (0.1)	$ (0.1)	$ (0.1)