Employee Stock Plans - Stock-Based Compensation Expense Included in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 27, 2020	Mar. 29, 2019	Mar. 29, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 3.1	$ 2.9	$ 2.9
Income tax benefit		(0.9)		(1.5)
Stock-based compensation expense, net of tax		2.2		1.4
Cost of Good Sold [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	[1]	0.4		0.6
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		0.1		0.1
Sales and Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		0.3		0.3
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 2.3		$ 1.9

[1] Stock-based compensation expense capitalized in inventory for the three months ended March 27, 2020 and March 29, 2019 was not significant.