Leases - Summary of Components of Lease Expense (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 26, 2020	Jun. 28, 2019	Jun. 26, 2020	Jun. 28, 2019
Leases [Abstract]
Operating lease cost	$ 3.4	$ 3.3	$ 6.6	$ 6.7
Short-term lease cost	0.3	0.4	0.6	0.6
Total lease cost	3.7	3.7	7.2	7.3
Operating cash flows from operating leases	$ 4.4	$ 3.7	$ 8.8	$ 3.7
Weighted-average remaining lease term – operating leases	2 years 2 months 12 days	2 years 3 months 18 days	2 years 2 months 12 days	2 years 3 months 18 days
Weighted-average discount rate – operating leases	5.50%	7.00%	5.50%	7.00%