Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 29, 2020	Dec. 29, 2019
Statement Of Financial Position [Abstract]
Allowances on accounts receivable	$ 258	$ 202
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	200,000,000	200,000,000
Common stock, outstanding	23,684,000	23,638,000
Treasury stock, shares	9,488,000	9,465,000