Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 26, 2020	Dec. 28, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 175,000	$ 938,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	3,000	3,000
Preferred stock, shares issued	0	0
Common Stock, Par or Stated Value Per Share		$ 0.01
Common Stock, Shares Authorized		120,000,000
Common Stock, Shares, Issued	91,059,407	88,912,796
Common Stock, Shares, Outstanding	85,443,378	82,536,416
Treasury stock, shares	2,564,155	4,513,256

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

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