Note 9 - Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 02, 2016	Jun. 27, 2015	Jul. 02, 2016	Jun. 27, 2015	Jan. 02, 2016	Dec. 27, 2014
Net income	$ 27,152	$ 28,684	$ 46,441	$ 48,679	$ 80,866	$ 98,100
Basic (in shares)	22,528	22,691	22,483	22,645
Net effect of dilutive stock options and restricted share units (in shares)	146	144	164	165
Average shares - Diluted (in shares)	22,674	22,835	22,647	22,810
Net income per share (see Note 9):
Net income per share - Basic (in dollars per share)	$ 1.21	$ 1.26	$ 2.07	$ 2.15	$ 3.58	$ 4.35
Net income per share - Diluted (in dollars per share)	$ 1.20	$ 1.26	$ 2.05	$ 2.13	$ 3.56	$ 4.32