Summary of Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended							4 Months Ended	12 Months Ended
	Dec. 30, 2017	Oct. 07, 2017	Mar. 25, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 09, 2016	Mar. 19, 2016	Jul. 15, 2017	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Quarterly Financial Information Disclosure [Line Items]
Net Sales	$ 48,685	$ 42,861	$ 31,866	$ 46,663	$ 39,657	$ 49,822	$ 35,520	$ 53,921	$ 177,333	$ 171,662	$ 159,463
Operating Income	5,144	4,128	1,996	3,771	5,329	3,005	2,478	3,332	14,600	14,583	12,818
Net income	$ 7,459	$ 3,118	$ 1,388	$ 3,463	$ 4,243	$ 2,090	$ 1,697	$ 2,096	$ 14,061	$ 11,493	$ 11,606
Basic Earnings Per Share Data:
Net Income (in dollars per share)	$ 0.52	$ 0.22	$ 0.1	$ 0.24	$ 0.30	$ 0.15	$ 0.12	$ 0.15	$ 0.98	$ 0.81	$ 0.82
Diluted Earnings Per Share Data:
Net Income (in dollars per share)	$ 0.52	$ 0.22	$ 0.1	$ 0.24	$ 0.30	$ 0.15	$ 0.12	$ 0.15	$ 0.98	$ 0.80	$ 0.82