Note 6 - Employee Benefit Plans - Stock Option Activity Under Share-based Compensation Plans (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Outstanding, beginning of year (in shares)	405	472	1,641
Outstanding, weighted average exercise price, beginning of year (in dollars per share)	$ 10.22	$ 10.20	$ 10.79
Exercised (in shares)	(42)	(67)	(1,164)
Exercised, weighted average exercise price (in dollars per share)	$ 9.82	$ 10.10	$ 10.98
Cancelled (in shares)			(5)
Cancelled, weighted average exercise price (in dollars per share)			$ 20.73
Outstanding, end of year (in shares)	363	405	472
Outstanding, weighted average exercise price, end of year (in dollars per share)	$ 10.27	$ 10.22	$ 10.20
Options exercisable at year end (in shares)	363	405	469
Options exercisable at year end, weighted average exercise price (in dollars per share)	$ 10.27	$ 10.22	$ 10.20