Restructuring and Transformation Programs - Costs Included in Selling, General & Administrative Expenses (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 4.0	$ 1.8	$ 11.2	$ 5.6
Severance and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	0.0	1.2	5.1	5.0
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 4.0	$ 0.0	$ 5.9	$ 0.0