Employee Stock Plans - Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 25, 2020	Dec. 27, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 15.8	$ 12.7	$ 12.1
Income tax benefit		(2.8)	(2.5)
Net stock-based compensation expense		13.0	10.2	12.1
Cost of Revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	[1]	2.0	1.8	2.4
Sales and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		1.3	1.3	1.3
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		0.2	0.1	0.3
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 12.3	$ 9.5	$ 8.1

[1] Stock-based compensation expenses capitalized in inventory for fiscal years 2021, 2020 and 2019 were considered immaterial.