Segment and Geographic Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 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	$ 37,674	$ 40,423
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	28,921	30,338
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	3,446	4,632
Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	3,237	3,883
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	1,014	958
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	353	313
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	703	299
Foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Total property and equipment, net	$ 8,753	$ 10,085