Note I - Equity-based Compensation (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	81 Months Ended
Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Number of Equity Incentive Plans from Which Future Equity Awards May Be Granted	2		2		2
Share-based Compensation Arrangement by Share-based Payment Award Number of Expired Equity Incentive Plans	3		3		3
Share-based Compensation Arrangement by Share-based Payment Award Number of Employee Purchase Plans	1		1		1
Allocated Share-based Compensation Expense, Total \| $	$ 1,752	$ 1,438	$ 5,111	$ 4,526
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total \| $	$ 6,290		$ 6,290		$ 6,290
Common Stock [Member]
Share Price \| $ / shares	$ 11.90		$ 11.90		$ 11.90
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	479,000		479,000		479,000
Equity Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	797,000		797,000		797,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value \| $ / shares	$ 10.93
Share-based Compensation Arrangement by Share-based Payment Award, Weighted Average Pre Vest Cancel Rate	4.36%
Stock Appreciation Rights (SARs) [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares to be Issued Upon Exercise of Outstanding Awards	1,922		1,922		1,922
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant as Percentage of Company Outstanding Common Stock					50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Exercisable, Number	785		785		785

The number of employee purchase plans held by the entity.

No definition available.

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- Definition

Represents the number of equity incentive plans, as of the balance sheet date, from which equity awards may be granted in the future.

+ References

No definition available.

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- Definition

The number of expired equity incentive plans from which no future equity awards may be granted but had outstanding equity awards granted prior to expiration.

+ References

No definition available.

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- Definition

Share-based compensation arrangement by share-based payment award, number of shares available for grant as percentage of company outstanding common stock

+ References

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- Definition

Share-based compensation arrangement by share-based payment award number of shares to be issued upon exercise of outstanding awards

+ References

No definition available.

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- Definition

Represents the number of exercisable options and stock appreciation rights related to a share-based compensation arrangement.

+ References

No definition available.

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- Definition

Weighted average pre vest cancellation rate.

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
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-Publisher FASB
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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 2
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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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

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