Business Segments - Revenue Information by Geographic Region (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 10,118	$ 9,526	$ 31,036	$ 27,675
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,547	5,572	16,236	14,743
Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	2,011	1,942	6,587	5,543
Rest of Americas
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	822	578	2,431	2,369
Asia/Pacific Rim
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 1,738	$ 1,434	$ 5,782	$ 5,020