Note 11 - Stock-based Compensation (Details) - Information Regarding Options Outstanding (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Information Regarding Options Outstanding [Abstract]
Outstanding at December 31, 2013		3,883,097
Outstanding at December 31, 2013		$ 9.26
Outstanding at December 31, 2013	6 years 43 days	6 years 120 days
Outstanding at December 31, 2013		$ 16,229
Outstanding at December 31, 2014	3,005,594
Outstanding at December 31, 2014	$ 10.16
Outstanding at December 31, 2014	6 years 43 days	6 years 120 days
Outstanding at December 31, 2014	25,302
Exercisable at December 31, 2014	2,349,476
Exercisable at December 31, 2014	$ 9.69
Exercisable at December 31, 2014	5 years 299 days
Exercisable at December 31, 2014	20,880
Vested and expected to vest in the future as of December 31, 2014	3,001,391
Vested and expected to vest in the future as of December 31, 2014	$ 10.16
Vested and expected to vest in the future as of December 31, 2014	6 years 43 days
Vested and expected to vest in the future as of December 31, 2014	$ 25,273
Exercised	(788,196)
Exercised	$ 5.45
Canceled	(89,307)
Canceled	$ 12.52

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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

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-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.

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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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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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Weighted average remaining contractual term for fully vested and expected to vest options 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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