Note 8 - Derivative Financial Instruments - Foreign Currency Forward Contracts Outstanding (Details) - Dec. 26, 2020 - Not Designated as Hedging Instrument [Member] € in Thousands, SFr in Thousands, $ in Millions	USD ($)	EUR (€)	CHF (SFr)
Swiss Franc Foreign Exchange Forward [Member] | Long [Member]
Contract amount	$ 15.0		SFr 13,349
Total Contract Amount	15.0		SFr 13,349
Euro Foreign Exchange Forward [Member] | Long [Member]
Contract amount	11.5	€ 9,424
Total Contract Amount	11.5	€ 9,424
Foreign Exchange Forward [Member]
Contract amount	26.5
Total Contract Amount	$ 26.5