Other Comprehensive (Loss) Income - Schedule of Reclassification From Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification, net of tax	$ 0.6	$ (4.7)
Other operating expense (income)	13.2	(4.4)
Interest expense-net	(33.9)	(40.1)
Translation Adjustments
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification, net of tax		(4.5)
Translation Adjustments | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other operating expense (income)		(4.5)
Net Actuarial Loss | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Investment and other income-net	1.6	1.5
Net Prior Service Credit | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Investment and other income-net	(0.6)	(1.8)
Amortization of Pension and OPEB Cost
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications before tax	1.0	(0.3)
Income tax expense (benefit)	0.2	(0.1)
Reclassification, net of tax	0.8	$ (0.2)
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification, net of tax	(0.2)
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest | Reclassification out of Accumulated Other Comprehensive Income | Net Realized Gain on Derivatives
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense-net	$ (0.2)