Business Segments - Revenue Information by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 9,789	$ 9,815	$ 33,628	$ 29,644
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,871	5,791	18,642	16,763
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	2,191	2,083	6,779	5,763
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	476	506	1,858	2,041
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 1,251	$ 1,435	$ 6,349	$ 5,077