Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 27, 2020	Dec. 28, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 241	$ 187
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	13,856,969	13,785,233
Common stock, shares outstanding	13,856,969	13,785,233