Note 12 - Financial Instruments and Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	9 Months Ended
Aug. 29, 2015	Nov. 29, 2014
Minimum [Member]
Certificates of Deposit Terms	180 days
Interest Rate of Certificates of Deposit	0.28%
Maximum [Member]
Certificates of Deposit Terms	1 year
Interest Rate of Certificates of Deposit	1.00%
Weighted Average [Member]
Certificates of Deposit Terms	300 days
Interest Rate of Certificates of Deposit	0.42%
Short-term Investments	$ 23,125	$ 23,125

Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph g

-Article 7

Name:	us-gaap_ShortTermInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant