Segment and Geographic Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 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	$ 36,418	$ 40,423
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	27,975	30,338
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	2,714	4,632
Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	3,664	3,883
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	1,004	958
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	361	313
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	700	299
Foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 8,443	$ 10,085