Note 17 - Stock Incentive Plans (Details Textual) - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
Jun. 25, 2018	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	3,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		22,210
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		2,276
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		240
Minimum [Member]
Employee Stock Purchase Plan, Payroll Deduction Per Employee, Percent		1.00%
Maximum [Member]
Employee Stock Purchase Plan, Payroll Deduction Per Employee, Percent		15.00%
The 2011 Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		2,093
2012 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		183
Common Stock, Capital Shares Reserved for Future Issuance		1,500
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Issued in 2017, Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Issued in 2018, Vesting Period One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Issued in 2018, Vesting Period Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Awards Issued in 2019, Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Payment Arrangement, Accelerated Cost		$ 112
Performance Share Units [Member] \| Granted Prior to 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Performance Share Units [Member] \| Grants in 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		2 years 182 days
Performance Share Units [Member] \| Share-based Compensation Awards Issued in 2019, Vesting Period [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share Based Payment Arrangement, Modification Expense		$ 102

The percentage of payroll deductions per employee under the employee stock purchase plan during the period.

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Amount of additional cost recognized for award under share-based payment arrangement from occurrence of event modifying recognition of cost.

+ References

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Aggregate number of common shares reserved for future issuance.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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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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Number of additional shares authorized for issuance under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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