CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Dec. 27, 2020	Dec. 29, 2019
Statement of Financial Position [Abstract]
Accounts receivable allowance	$ 2,921	$ 4,288
Preferred stock, par value (in dollars per share)	$ 0.131	$ 0.131
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	35,493,000	38,593,000
Common stock, shares outstanding	35,493,000	38,593,000