Note 6 - Stock-Based Compensation (Details) - Summary of Related Activity Under the Incentive Plan (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of Related Activity Under the Incentive Plan [Abstract]
Awards Available	2,362	1,082	2,815	2,009
Options Outstanding	9,605	8,986	8,073	7,858
Weighted Average Exercise Price (in Dollars per share)	$ 6.21	$ 4.99	$ 6.09	$ 6.21
Awards Available	3,750		1,700
Awards Available	(593)	(310)	(415)
Awards Available		53	86
Awards Available	(1,965)	(3,277)	(1,617)
Options Outstanding	1,965	3,277	1,617
Weighted Average Exercise Price (in Dollars per share)	$ 10.99	$ 3.05	$ 4.65
Options Outstanding	(1,258)	(563)	(350)
Weighted Average Exercise Price (in Dollars per share)	$ 4.78	$ 2.37	$ 1.58
Awards Available	88	1,801	1,052
Options Outstanding	(88)	(1,801)	(1,052)
Weighted Average Exercise Price (in Dollars per share)	$ 8.83	$ 7.22	$ 6.26

Share based compensation arrangement by share based payment award options forfeitures in period awards available.

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Represents share based compensation arrangement by share based payment award options grants in period awards available.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(3)

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The number of grants made 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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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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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

+ References

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Weighted average price of options that were either forfeited or expired.

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- Definition

Net number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Other than shares newly issued, the number of additional shares issued (for example, a stock split) or canceled (for example, to correct a share issuance), during the period under the plan.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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