Note 5 - Financial Instruments Measured at Fair Value - Effective Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Jun. 28, 2025	Dec. 28, 2024
Due in one year or less, amortized cost	$ 33,170	$ 47,819
Due in one year or less, fair value	33,173	47,855
Due after one year through five years, amortized cost	11,783	7,847
Due after one year through five years, fair value	11,802	7,830
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost, Total	44,953	55,666
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value, Total	$ 44,975	$ 55,685

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Publisher FASB
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
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