Note 5 - Financial Instruments Measured at Fair Value - Effective Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Mar. 30, 2024	Dec. 30, 2023
Due in one year or less, amortized cost	$ 51,055	$ 57,981
Due in one year or less, fair value	50,992	57,887
Due after one year through five years, amortized cost	28,485	31,378
Due after one year through five years, fair value	28,535	31,546
Due after five years through ten years, amortized cost	730	741
Due after five years through ten years	730	741
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost, Total	80,270	90,100
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value, Total	$ 80,257	$ 90,174