Note 2 - Effects of Adjustments to Correct Immaterial Errors, Statements of Net Income (Details) - USD ($) $ / shares in Units, $ 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
Scenario, Previously Reported [Member]
Income Tax Expense (Benefit)					$ 24,482	$ 32,228
Net income					$ 82,466	$ 99,418
Net income per share - Basic (in dollars per share)					$ 3.65	$ 4.41
Net income per share - Diluted (in dollars per share)					$ 3.63	$ 4.37
Restatement Adjustment [Member]
Income Tax Expense (Benefit)					$ 1,600	$ 1,318
Net income					$ (1,600)	$ (1,318)
Net income per share - Basic (in dollars per share)					$ (0.07)	$ (0.06)
Net income per share - Diluted (in dollars per share)					$ (0.07)	$ (0.05)
Income Tax Expense (Benefit)	$ 6,862	$ 9,033	$ 14,650	$ 15,444	$ 26,082	$ 33,546
Net income	$ 27,152	$ 28,684	$ 46,441	$ 48,679	$ 80,866	$ 98,100
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