Note 9 - Stock-based Compensation (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Apr. 03, 2021	Mar. 28, 2020
Share-based Payment Arrangement, Expense	$ 10,454	$ 8,728
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Expense		1,800
Restricted Stock Units (RSUs) [Member] \| Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)	3 years
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved	75.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved	75.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| TSR Relative To PHLX Semiconductor Sector Index, 55th Percentile [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions	100.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions	200.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved	55.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	0.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Minimum [Member] \| TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions	250.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Minimum [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved	25.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions	200.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Maximum [Member] \| TSR Relative To PHLX Semiconductor Sector Index, 75th Percentile [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage, Based on Market Conditions	200.00%
Restricted Stock Units (RSUs) [Member] \| Executive Officer [Member] \| Maximum [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Of Market Condition Achieved	75.00%
Performance Shares [Member] \| Executive Officer [Member]
Share-based Payment Arrangement, Expense	$ 4,600	$ 4,200

Percentage of vesting of award under share-based payment arrangement based on market conditions.

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The percentage of market condition achieved for awards to vest under share based payment arrangement.

+ References

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

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-Publisher FASB
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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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