Summary of Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						4 Months Ended		12 Months Ended
	Dec. 28, 2019	Oct. 05, 2019	Mar. 23, 2019	Dec. 29, 2018	Oct. 06, 2018	Mar. 24, 2018	Jul. 13, 2019	Jul. 14, 2018	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Summary of Quarterly Results
Net Sales	$ 47,044	$ 45,756	$ 32,102	$ 50,992	$ 43,955	$ 32,149	$ 55,639	$ 48,684	$ 180,541	$ 175,780	$ 177,333
Operating Income	3,511	2,899	394	5,017	5,134	1,715	2,471	1,951	9,275	13,817	14,600
Net income	$ 2,575	$ 2,540	$ 267	$ 3,580	$ 3,575	$ 1,216	$ 1,876	$ 12,071	$ 7,258	$ 20,442	$ 14,061
Basic Earnings Per Share Data:
Net Income (in dollars per share)	$ 0.18	$ 0.18	$ 0.02	$ 0.25	$ 0.25	$ 0.08	$ 0.13	$ 0.84	$ 0.50	$ 1.42	$ 0.98
Diluted Earnings Per Share Data:
Net Income (in dollars per share)	$ 0.18	$ 0.18	$ 0.02	$ 0.25	$ 0.25	$ 0.08	$ 0.13	$ 0.84	$ 0.50	$ 1.41	$ 0.98