Balance Sheet Components (Property and Equipment) (Details) - USD ($) $ in Thousands	Jun. 29, 2019	Dec. 29, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment, net	$ 39,593	$ 34,883
United States
Property, Plant and Equipment [Line Items]
Total property and equipment, net	33,370	27,353
Foreign countries
Property, Plant and Equipment [Line Items]
Total property and equipment, net	6,223	7,530
China
Property, Plant and Equipment [Line Items]
Total property and equipment, net	1,871	2,360
Philippines
Property, Plant and Equipment [Line Items]
Total property and equipment, net	2,983	3,319
Taiwan
Property, Plant and Equipment [Line Items]
Total property and equipment, net	699	949
Japan
Property, Plant and Equipment [Line Items]
Total property and equipment, net	236	324
Other
Property, Plant and Equipment [Line Items]
Total property and equipment, net	$ 434	$ 578