Stock-Based Compensation Stock comp expense classification (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Share-based Payment Arrangement, Expense	$ 23,744	$ 25,804	$ 19,751
Share-based Payment Arrangement, Noncash Expense	23,744	25,804	19,751
Cost of revenue
Share-based Payment Arrangement, Expense	1,486	1,407	1,082
Research and Development Expense [Member]
Share-based Payment Arrangement, Expense	9,186	7,494	5,009
Selling and Marketing Expense [Member]
Share-based Payment Arrangement, Expense	3,323	2,842	2,571
General and Administrative Expense [Member]
Share-based Payment Arrangement, Expense	$ 9,749	$ 14,061	$ 11,089