Note 4 - Stock-based Compensation (Details) - Stock Options Activity (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
Stock Options Activity [Abstract]
Number of options outstanding	76	221	333	437
Weighted average exercise price of options outstanding	$ 14.73	$ 14.98	$ 15.67	$ 14.66
Weighted average remaining contractual term of options outstanding	6 months	1 year	1 year 6 months	2 years 36 days
Aggregate intrinsic value of options outstanding	$ 945
Exercisable at December 31, 2014	76
Exercisable at December 31, 2014	$ 14.73
Exercisable at December 31, 2014	6 months
Exercisable at December 31, 2014	$ 945
Number of options exercised	(45)
Weighted average exercise price of options exercised	$ 13.64
Number of options forfeited	(100)	(112)	(104)
Weighted average exercise price of options forfeited	$ 21.71	$ 17.14	$ 12.27

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ 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)(iii)

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

+ References

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

-Publisher FASB

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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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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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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

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