Note 16 - Stock Incentive Plans (Details Textual) - shares shares in Thousands		12 Months Ended
Jun. 25, 2018	Dec. 31, 2018
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		2,370
Stock Repurchase Program, Number of Shares Authorized to be Repurchased		100
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		2,030
2012 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		340
Common Stock, Capital Shares Reserved for Future Issuance		1,500
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Issued Prior to December 31, 2010, Vesting Period Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Issued Prior to December 31, 2010, Vesting Period Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		5 years
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Issued in 2011, 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, Granted in 2012, Vesting Period One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year
Restricted Stock Units (RSUs) [Member] \| Share-based Compensation Award, Granted in 2012, Vesting Period Two [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 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 Award, Issued Prior to December 31, 2010, Vesting Period One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Long-term Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		5 years
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting Period, When Three Years of Profitability Criteria is Met		3 years
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
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

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

No definition available.

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- Definition

The accelerated period which an employee's right to exercise an award if three-year profitability criteria are met, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the 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 (a)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

+ References

No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ 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 (a)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

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.

+ 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
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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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.

+ References

No definition available.

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