Note 13 - Segment Information (Details Textual) $ in Thousands	3 Months Ended	9 Months Ended
Aug. 31, 2019 USD ($)	Aug. 25, 2018 USD ($)	Aug. 31, 2019 USD ($)	Aug. 25, 2018 USD ($)
Number of Reportable Segments			3
Zenith Freight Lines [Member]
Operating Expenses, Total	$ 18,289	$ 19,979	$ 59,298	$ 62,011

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

No definition available.

Name:	us-gaap_OperatingExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration