Note 13 - Segment Information (Details Textual) $ in Thousands	3 Months Ended	9 Months Ended
Aug. 26, 2017 USD ($)	Aug. 27, 2016 USD ($)	Aug. 26, 2017 USD ($)	Aug. 26, 2017	Aug. 27, 2016 USD ($)
Number of Reportable Segments				3
Zenith Operating Costs Included in Selling, General and Administrative Expenses	$ 23,761	$ 22,317	$ 70,149		$ 69,401

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration