Stock-Based Compensation Expense - Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 9,002	$ 7,846	$ 22,196	$ 15,329
Cost of Revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	557	454	1,354	884
Research, Development, and Engineering Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,154	2,715	7,969	5,325
Selling, General, and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 5,291	$ 4,677	$ 12,873	$ 9,120