Computation of Basic and Diluted Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Numerators:
Consolidated net income	$ 11,664	$ 11,660	$ 22,974	$ 23,607
Denominators:
Weighted average common shares outstanding—basic	35,374	35,137	35,326	35,145
Dilutive potential common shares	389	442	449	425
Weighted average common shares outstanding— diluted	35,763	35,579	35,775	35,570
Antidilutive potential common shares excluded from above	25		23	26
Earnings per Common Share:
Basic	$ 0.33	$ 0.33	$ 0.65	$ 0.67
Diluted	$ 0.33	$ 0.33	$ 0.64	$ 0.66