Accumulated Other Comprehensive Loss - Amounts Reclassified Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	$ (16.7)	$ (21.9)	$ (213.6)	$ (42.9)
Total before tax	(24.1)	3.5	(178.7)	(49.4)
Income tax	(15.4)	(20.3)	(35.3)	(24.4)
Reclassification out of Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	18.1	40.7	218.0	80.5
Income tax	(0.4)	(1.5)	(0.8)	(3.2)
Total reclassifications for the period	17.7	39.2	217.2	77.3
Reclassification out of Accumulated Other Comprehensive Loss | Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	0.1	1.8	(3.4)	2.9
Reclassification out of Accumulated Other Comprehensive Loss | Amortization of prior service benefit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	(1.3)	(1.2)	(2.6)	(2.9)
Reclassification out of Accumulated Other Comprehensive Loss | Amortization of actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	19.3	40.1	40.8	80.5
Reclassification out of Accumulated Other Comprehensive Loss | Settlement losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	$ 0.0	$ 0.0	$ 183.2	$ 0.0