Business Segments - Revenue Information by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2016	Apr. 04, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 11,931	$ 10,796
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,848	5,581
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	2,291	2,314
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	620	996
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 3,172	$ 1,905