Certain Significant Estimates (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Product Warranty [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 1,308	$ 869	$ 656
Additions	1,045	1,524	1,087
Deductions	(1,378)	(1,085)	(874)
Ending balance	975	1,308	869
Inventory Valuation Reserves [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	2,100	1,556	1,839
Additions	1,019	929	458
Deductions	(1,008)	(385)	(741)
Ending balance	2,111	2,100	1,556
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	1,096	938	1,204
Additions	639	450	1,125
Deductions	(414)	(292)	(1,391)
Ending balance	1,321	1,096	938
Customer Allowances [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	2,681	2,605	2,398
Additions	6,363	6,712	5,762
Deductions	(5,759)	(6,636)	(5,555)
Ending balance	$ 3,285	$ 2,681	$ 2,605