Note 12 - Summary of Quarterly Results - Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						4 Months Ended		12 Months Ended
	Dec. 25, 2021	Oct. 02, 2021	Mar. 20, 2021	Dec. 26, 2020	Oct. 03, 2020	Mar. 21, 2020	Jul. 10, 2021	Jul. 11, 2020	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Net Sales	$ 73,444	$ 81,298	$ 59,191	$ 74,767	$ 78,069	$ 37,289	$ 99,679	$ 83,524	$ 313,612	$ 273,649	$ 180,541
Operating income (loss)	6,409	7,672	7,129	6,921	12,815	2,424	10,686	10,872	31,896	33,032	9,275
Net Income	$ 4,871	$ 5,966	$ 5,442	$ 5,087	$ 10,186	$ 1,951	$ 8,126	$ 8,710	$ 24,405	$ 25,934	$ 7,258
Basic Earnings Per Share Data: (in dollars per share)	$ 0.36	$ 0.44	$ 0.39	$ 0.36	$ 0.72	$ 0.14	$ 0.59	$ 0.62	$ 1.78	$ 1.84	$ 0.50
Diluted Earnings Per Share Data: (in dollars per share)	$ 0.36	$ 0.43	$ 0.39	$ 0.36	$ 0.71	$ 0.14	$ 0.58	$ 0.61	$ 1.76	$ 1.82	$ 0.50