Note 7 - Bank Credit Facility (Details Textual) $ in Thousands	Feb. 27, 2021 USD ($)
Bank One [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 25,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.25%
Bank One [Member] | London Interbank Offered Rate (LIBOR) [Member]
Letters of Credit Outstanding, Amount	$ 3,181
Line of Credit Facility, Remaining Borrowing Capacity	$ 21,819
Debt Instrument, Basis Spread on Variable Rate	1.90%
Bank Two [Member]
Letters of Credit Outstanding, Amount	$ 325