Note 6 - Employee Stock Benefit Plans - Stock Options Outstanding and Exercisable (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Number Outstanding (in shares)	1,641	1,965	2,435	3,086
Options Outstanding, Weighted Average Remaining Life (Year)	4 years
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 10.79	$ 11.25	$ 11.67	$ 11.93
Options Exercisable (in shares)	1,537	1,673	1,901
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 10.85	$ 11.47	$ 12.08
Range 1 [Member]
Range of Exercise Prices, Lower (in dollars per share)	7.32
Range of Exercise Prices, Upper (in dollars per share)	$ 10.58
Number Outstanding (in shares)	1,089
Options Outstanding, Weighted Average Remaining Life (Year)	4 years 146 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 8.92
Options Exercisable (in shares)	1,002
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 8.87
Range 2 [Member]
Range of Exercise Prices, Lower (in dollars per share)	10.59
Range of Exercise Prices, Upper (in dollars per share)	$ 15.50
Number Outstanding (in shares)	466
Options Outstanding, Weighted Average Remaining Life (Year)	3 years 73 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.08
Options Exercisable (in shares)	449
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 14.20
Range 3 [Member]
Range of Exercise Prices, Lower (in dollars per share)	15.51
Range of Exercise Prices, Upper (in dollars per share)	$ 20.73
Number Outstanding (in shares)	86
Options Outstanding, Weighted Average Remaining Life (Year)	3 years 73 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 16.55
Options Exercisable (in shares)	86
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 16.55