Note 7 - Income Taxes (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Domestic Tax Authority [Member]
Operating Loss Carryforwards	$ 19,300
Tax Credit Carryforward, Amount	6,700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	21,300
Tax Credit Carryforward, Amount	13,600
Foreign Tax Authority [Member]
Operating Loss Carryforwards	$ 1,600
Minimum [Member]
Collection Term Range	4 years
Maximum [Member]
Collection Term Range	10 years
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 1,400	$ 1,400
Cumulative Three Year Pre-tax Income (Loss)	(27,300)
Deferred Tax Assets, Valuation Allowance	42,289	37,023
Income Tax Credits and Adjustments	400	500	$ 700
Undistributed Earnings of Foreign Subsidiaries	41,000
Increase (Decrease) of Net Income Due to Impact of Tax Holidays	$ 800
Increase (Decrease) of Earning Per Share Due To Impact Of Tax Holidays	$ 0.03
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 5,600	$ 6,200
Decrease in Unrecognized Tax Benefits is Reasonably Possible	500
Unrecognized Tax Benefits, Interest Expense, Net of Accrued Interest Reversed	$ 100		$ (100)