GEOGRAPHIC AND CUSTOMER CONCENTRATION INFORMATION - Summary of Geographic Information Relating to Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 27, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 8,754	$ 7,534
Reportable Geographical Components | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	3,590	4,140
Reportable Geographical Components | Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	4,970	3,185
Reportable Geographical Components | Others
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 194	$ 209