Business Segments - Revenue Information by Geographic Region (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 10,589	$ 9,210	$ 20,918	$ 18,149
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,984	4,962	10,689	9,171
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	2,273	1,628	4,576	3,601
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	771	941	1,609	1,791
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 1,561	$ 1,679	$ 4,044	$ 3,586