Note 4 - Goodwill and Purchased Intangible Assets (Details Textual) - USD ($) $ in Millions		12 Months Ended
	Sep. 24, 2015	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Trade Names [Member]
Finite-Lived Intangible Asset, Useful Life	15 years	14 years 255 days
Amortization of Intangible Assets		$ 7.0	$ 7.8	$ 7.8
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		6.8
Finite-Lived Intangible Assets, Amortization Expense, Year Two		3.7
Finite-Lived Intangible Assets, Amortization Expense, Year Three		3.7
Finite-Lived Intangible Assets, Amortization Expense, Year Four		3.7
Finite-Lived Intangible Assets, Amortization Expense, after Year Five		3.7
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 3.7