Nature of Operations and Summary of Significant Accounting Policies (Details 2) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Nature Of Operations and Summary Of Significant Accounting Policies [Line Items]
Land	$ 1,943	$ 1,943
Buildings and leasehold improvements	16,392	15,733
Machinery and equipment	24,453	22,379
Total cost	42,788	40,055
Accumulated depreciation and amortization	(28,502)	(26,341)
Property, Plant and Equipment	$ 14,286	$ 13,714