Note 6 - Employee Stock Benefit Plans - Stock Option Activity under Share-based Compensation Plans (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Outstanding, beginning of year (in shares)	1,965	2,435	3,086
Outstanding, beginning of year (in dollars per share)	$ 11.25	$ 11.67	$ 11.93
Granted (in shares)		10	10
Granted (in dollars per share)		$ 10.98	$ 12.58
Exercised (in shares)	(101)	(175)	(237)
Exercised (in dollars per share)	$ 7.89	$ 8.65	$ 8.43
Cancelled (in shares)	(223)	(305)	(424)
Cancelled (in dollars per share)	$ 16.19	$ 16.07	$ 15.37
Outstanding, end of year (in shares)	1,641	1,965	2,435
Outstanding, end of year (in dollars per share)	$ 10.79	$ 11.25	$ 11.67
Options exercisable at year end (in shares)	1,537	1,673	1,901
Options exercisable at year end (in dollars per share)	$ 10.85	$ 11.47	$ 12.08