Pension Plans - Components of Net Periodic Pension Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.0	$ 0.0	$ 0.0
Interest cost	1.2	1.3	1.2
Expected return on plan assets	(1.3)	(1.3)	(1.4)
Amortization of net loss	0.0	0.0	0.0
Amortization of prior service cost	0.0	0.0	0.0
Net curtailment and settlement loss recognized	0.0	0.0	0.0
Net periodic pension cost	(0.1)	0.0	(0.2)
Non-U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4.4	2.2	1.0
Interest cost	4.0	5.3	5.3
Expected return on plan assets	(5.4)	(5.5)	(5.4)
Amortization of net loss	4.1	2.5	2.4
Amortization of prior service cost	0.3	0.2	0.0
Net curtailment and settlement loss recognized	(0.5)	0.2	0.9
Net periodic pension cost	$ 6.9	$ 4.9	$ 4.2