Note 4 - Financial Instruments, Investments and Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Nov. 25, 2017	Nov. 26, 2016
Short-term Investments	$ 23,125	$ 23,125
Minimum [Member]
Certificates of Deposit Terms	180 days
Interest Rate of Certificates of Deposit	0.10%
Maximum [Member]
Certificates of Deposit Terms	1 year
Interest Rate of Certificates of Deposit	1.50%
Weighted Average [Member]
Certificates of Deposit Terms	150 days
Interest Rate of Certificates of Deposit	1.18%