Accumulated Other Comprehensive Loss - Amounts Reclassified Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	$ (23.3)	$ (24.2)	$ (66.2)	$ (434.6)
Total before tax	(39.2)	(7.6)	(88.6)	(352.1)
Income tax	(0.7)	(10.9)	(25.1)	33.8
Reclassification out of Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	40.3	41.4	120.8	427.4
Income tax	(1.4)	(1.4)	(4.6)	(40.0)
Total reclassifications for the period	38.9	40.0	116.2	387.4
Reclassification out of Accumulated Other Comprehensive Loss | Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	1.9	(1.3)	4.8	(2.9)
Reclassification out of Accumulated Other Comprehensive Loss | Amortization of prior service cost
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	(1.6)	(1.6)	(4.5)	(4.7)
Reclassification out of Accumulated Other Comprehensive Loss | Amortization of actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	40.0	44.3	120.5	134.3
Reclassification out of Accumulated Other Comprehensive Loss | Settlement losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	$ 0.0	$ 0.0	$ 0.0	$ 300.7