Supplemental Financial Statement Information - Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, gross	$ 1,390.2	$ 1,277.6
Accumulated depreciation	(705.7)	(553.8)
Property, Plant and Equipment, net	684.5	723.8
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, gross	60.5	57.4
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, gross	339.8	333.3
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, gross	916.7	849.9
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, gross	$ 73.2	$ 37.0