Other Income (Expense) - Net - Computation of Other Income (Expense) - Net (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Other Income and Expenses [Abstract]
Interest income	$ 0.5	$ 0.4	$ 1.2	$ 1.1
Net foreign exchange loss	(0.4)	(0.2)	(3.0)	(2.7)
Net periodic pension and postretirement benefits – non-service	2.6	2.5	8.0	7.5
Other	0.1	0.1	0.1	0.5
Total other income (expense) – net	$ 2.8	$ 2.8	$ 6.3	$ 6.4