Defined Benefit Pension Plans and Other Post-Employment Benefit Plans - Components of Net Periodic Benefit Cost (Income) for Defined Benefit Pension Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Components of net periodic benefit (income) cost:
Service cost	$ 1.3	$ 1.1
Interest cost	3.1	4.3
Expected return on plan assets	(6.9)	(7.2)
Amortization of net prior service credit and net actuarial gain	0.1	0.0
Amortization of net actuarial loss	1.9	1.6
Net periodic (income) cost	(0.5)	(0.2)
Cost of settlement	0.1	0.0
Total benefit (income) cost	(0.4)	(0.2)
U.S.
Components of net periodic benefit (income) cost:
Service cost	0.0	0.0
Interest cost	0.9	1.3
Expected return on plan assets	(2.2)	(2.2)
Amortization of net prior service credit and net actuarial gain	0.0	0.0
Amortization of net actuarial loss	0.6	0.4
Net periodic (income) cost	(0.7)	(0.5)
Cost of settlement	0.0	0.0
Total benefit (income) cost	(0.7)	(0.5)
International
Components of net periodic benefit (income) cost:
Service cost	1.3	1.1
Interest cost	2.2	3.0
Expected return on plan assets	(4.7)	(5.0)
Amortization of net prior service credit and net actuarial gain	0.1	0.0
Amortization of net actuarial loss	1.3	1.2
Net periodic (income) cost	0.2	0.3
Cost of settlement	0.1	0.0
Total benefit (income) cost	$ 0.3	$ 0.3