Accumulated Other Comprehensive Loss - Amounts Reclassified Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	$ (21.0)	$ (182.6)
Total before tax	(52.9)	(149.1)
Income tax	(4.1)	(8.4)
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	39.8	199.0
Income tax	(1.7)	(1.7)
Total reclassifications for the period	38.1	197.3
Reclassification out of Accumulated Other Comprehensive Income | Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	1.1	(2.3)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of prior service cost
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	(1.7)	(1.5)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	40.4	44.8
Reclassification out of Accumulated Other Comprehensive Income | Settlement losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other (expense), net	$ 0.0	$ 158.0