Defined Benefit Pension Plans and Other Post-Employment Benefit Plans - Net Period Benefit Costs (Income) for Post-retirement Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Components of net periodic benefit cost:
Interest cost	$ 7.0	$ 4.1	$ 14.0	$ 8.1
Net periodic cost (income)	1.9	(0.7)	3.9	(1.3)
Other post-retirement employee benefit plans
Components of net periodic benefit cost:
Interest cost	0.4	0.2	0.8	0.4
Amortization of net prior service credit and net actuarial gain	(0.1)	(0.1)	(0.2)	(0.2)
Net periodic cost (income)	$ 0.3	$ 0.1	$ 0.6	$ 0.2