Note 7 - Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Balance at beginning of year	$ 10,444	$ 10,841	$ 10,483
Gross additions for tax positions of current year	125	215	761
Gross additions for tax positions of prior years	58	248	365
Reductions due to lapse of the statute of limitations	(446)	(243)	(587)
Foreign exchange rate impact	(106)	(617)	(181)
Balance at end of year	$ 10,075	$ 10,444	$ 10,841

Amount of unrecognized tax benefits.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

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