Note 6 - Employee Benefit Plans - Stock Options Outstanding and Exercisable (Details) shares in Thousands	12 Months Ended
	Dec. 26, 2020 $ / shares shares
Options outstanding, number (in shares) | shares	262
Options outstanding, weighted average remaining life (Year)	1 year 10 months 24 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 10.01
Options exercisable, number (in shares) | shares	262
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.01
Range 1 [Member]
Lower limit (in dollars per share)	9.44
Upper limit (in dollars per share)	$ 10.54
Options outstanding, number (in shares) | shares	159
Options outstanding, weighted average remaining life (Year)	2 years 2 months 12 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 9.50
Options exercisable, number (in shares) | shares	159
Options exercisable, weighted average exercise price (in dollars per share)	$ 9.50
Range 2 [Member]
Lower limit (in dollars per share)	10.55
Upper limit (in dollars per share)	$ 10.58
Options outstanding, number (in shares) | shares	92
Options outstanding, weighted average remaining life (Year)	1 year 2 months 12 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 10.58
Options exercisable, number (in shares) | shares	92
Options exercisable, weighted average exercise price (in dollars per share)	$ 10.58
Range 3 [Member]
Lower limit (in dollars per share)	10.59
Upper limit (in dollars per share)	$ 12.58
Options outstanding, number (in shares) | shares	11
Options outstanding, weighted average remaining life (Year)	3 years 6 months
Options outstanding, weighted average exercise price (in dollars per share)	$ 12.44
Options exercisable, number (in shares) | shares	11
Options exercisable, weighted average exercise price (in dollars per share)	$ 12.44