Retirement and Other Postretirement Benefit Plans - Schedule of Net Periodic Benefit Costs of Defined Benefit Retirement Plans (Details) - Defined Benefit Retirement Plans - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
U.S.
Net periodic benefit costs of defined benefit retirement plans
Service cost	$ 0.3	$ 0.3	$ 0.5	$ 0.6
Interest cost		0.1	0.1	0.2
Net amortization and deferral	0.2	0.1	0.4	0.2
Net periodic benefit cost (credit)	$ 0.5	$ 0.5	$ 1.0	$ 1.0
Defined Benefit Plan, Tax Status [Extensible List]	Non-qualified	Non-qualified	Non-qualified	Non-qualified	Non-qualified
European
Net periodic benefit costs of defined benefit retirement plans
Service cost	$ 0.3	$ 0.3	$ 0.5	$ 0.5
Interest cost	0.6	0.8	1.1	1.7
Expected return on plan assets	(0.9)	(1.7)	(1.8)	(3.4)
Net amortization and deferral	0.2	0.1	0.5	0.2
Net periodic benefit cost (credit)	$ 0.2	$ (0.5)	$ 0.3	$ (1.0)