Restructuring and Transformation Programs - Costs Included in Selling, General & Administrative Expenses (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 6.1	$ 1.1	$ 7.2	$ 3.8
Severance and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	4.2	1.1	5.1	3.8
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1.9	$ 0.0	$ 2.1	$ 0.0