Summary of Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 09, 2016	Mar. 19, 2016	Dec. 26, 2015	Oct. 03, 2015	Jul. 11, 2015	Mar. 21, 2015	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Quarterly Financial Information Disclosure [Line Items]
Net Sales	$ 45,826	$ 38,793	$ 48,463	$ 34,568	$ 43,744	$ 34,584	$ 43,795	$ 33,419	$ 167,650	$ 155,542	$ 137,975
Operating income	3,771	5,329	3,005	2,478	2,501	1,873	4,157	4,287	14,583	12,818	15,504
Net income	$ 3,463	$ 4,243	$ 2,090	$ 1,697	$ 2,859	$ 2,028	$ 3,222	$ 3,497	$ 11,493	$ 11,606	$ 11,817
Basic Earnings Per Share Data:
Net Income (in dollars per share)	$ 0.24	$ 0.30	$ 0.15	$ 0.12	$ 0.20	$ 0.14	$ 0.23	$ 0.25	$ 0.81	$ 0.82	$ 0.85
Diluted Earnings Per Share Data:
Net income	$ 0.24	$ 0.30	$ 0.15	$ 0.12	$ 0.20	$ 0.14	$ 0.23	$ 0.25	$ 0.8	$ 0.82	$ 0.84