Note 8 - Derivative Financial Instruments - Locations and Amounts of Gains (Loss) (Details) $ in Thousands	12 Months Ended
Dec. 26, 2020 USD ($)
Foreign Currency Gain (Loss) [Member] \| Foreign Exchange Forward [Member] \| Not Designated as Hedging Instrument [Member]
Foreign exchange forward contracts	$ 756

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5618551-113959

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration