Note 4 - Financial Instruments and Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Aug. 27, 2016	Nov. 28, 2015
Maximum [Member]
Certificates of Deposit Terms	1 year
Interest Rate of Certificates of Deposit	1.00%
Minimum [Member]
Interest Rate of Certificates of Deposit	0.28%
Weighted Average [Member]
Certificates of Deposit Terms	300 days
Interest Rate of Certificates of Deposit	0.65%
Short-term Investments	$ 23,125	$ 23,125