Note 11 - Stock-Based Compensation Plans - Share-based Payment Award Stock Options Valuation Assumptions (Details) - Employee Stock Purchase Plan [Member]	12 Months Ended
Jan. 01, 2022	Jan. 02, 2021	Dec. 28, 2019
Weighted average expected volatility	39.90%	48.20%	31.60%
Weighted average risk-free interest rate	0.07%	0.89%	2.51%
Expected term (years) (Year)	6 years	6 years	6 years

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Rate of weighted-average expected volatility for award under share-based payment arrangement.

+ References

+ Details

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809

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