Note 6 - Employee Benefit Plans - Restricted Stock Unit Activity Under Share-based Compensation Plans (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 25, 2021	Dec. 26, 2020
Outstanding, beginning of year, units (in shares)	1,058	1,414	1,328
Outstanding, beginning of year, wt. avg. (in dollars per share)	$ 21.16	$ 15.16	$ 17.05
Granted, units (in shares)	431	270	779
Granted, wt. avg. (in dollars per share)	$ 27.74	$ 41.66	$ 14.02
Released, units (in shares)	(474)	(579)	(621)
Released, wt. avg. (in dollars per share)	$ 19.94	$ 16.23	$ 17.48
Cancelled, units (in shares)	(46)	(47)	(72)
Cancelled, wt. avg. (in dollars per share)	$ 24.33	$ 18.96	$ 17.59
Outstanding, end of year, units (in shares)	969	1,058	1,414
Outstanding, end of year, wt. avg. (in dollars per share)	$ 24.55	$ 21.16	$ 15.16