Business Segments - Revenue Information by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 9,033	$ 10,589	$ 19,829	$ 20,918
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,391	5,984	10,972	10,689
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	1,366	2,273	3,680	4,576
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	539	771	1,535	1,609
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 1,737	$ 1,561	$ 3,642	$ 4,044