Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 26, 2020	Dec. 28, 2019
Statement of Financial Position [Abstract]
Trade receivables, allowances	$ 386	$ 236
Common stock, par value	$ .001	$ 0.001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	27,560,686	27,413,626
Common stock, shares outstanding	27,560,686	27,413,626

Amount of allowance for credit loss on accounts receivable, classified as current.

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Face amount or stated value per share of common stock.

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