Segment and Geographic Information (Details) $ in Thousands	9 Months Ended
	Sep. 29, 2018 USD ($) segment	Dec. 30, 2017 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | segment	1
Total property and equipment, net	$ 35,724	$ 40,423
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	27,893	30,338
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	2,357	4,632
Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	3,472	3,883
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	1,062	958
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	319	313
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	621	299
Foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 7,831	$ 10,085