Stock-Based Compensation Expense - Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 10,194	$ 9,143	$ 33,442	$ 31,339
Cost of Revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	334	544	1,114	1,898
Research, Development, and Engineering Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,616	3,197	11,633	11,166
Selling, General, and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 6,244	$ 5,402	$ 20,695	$ 18,275