Business Segments - Revenue Information by Geographic Region (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 04, 2015	Mar. 29, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 10,796	$ 10,329
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,581	4,705
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	2,314	2,303
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	996	838
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 1,905	$ 2,483