Balance Sheet Components (Property and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2014	Dec. 29, 2013
Property and equipment:
Property and equipment, gross	$ 18,684	$ 17,993
Accumulated depreciation and amortization	(15,467)	(15,153)
Property and equipment, net	3,217	2,840
Equipment [Member]
Property and equipment:
Property and equipment, gross	14,047	13,294
Software [Member]
Property and equipment:
Property and equipment, gross	3,332	3,349
Furniture and Fixtures [Member]
Property and equipment:
Property and equipment, gross	710	710
Leasehold Improvements [Member]
Property and equipment:
Property and equipment, gross	$ 595	$ 640