Note 6 - Stock-based Compensation (Details Textual) - shares	1 Months Ended	12 Months Ended
May 31, 2012	Dec. 31, 2004
2004 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		3,750,000
2004 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member] \| Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		2 years
2004 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member] \| Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
2004 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member] \| Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
2004 Stock Incentive Plan [Member] \| Employee Stock Option [Member] \| Non Employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		1 year
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
2012 Stock Incentive Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	6 years
2012 Stock Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
2012 Stock Incentive Plan [Member] \| Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	400,000
2012 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,000,000
2012 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member] \| Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	2 years
2012 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member] \| Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
2012 Stock Incentive Plan [Member] \| Stock Options And Stock Appreciation Rights [Member] \| Share-based Compensation Award, Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	50.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
2012 Stock Incentive Plan [Member] \| Employee Stock Option [Member] \| Non Employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Percentage of vesting of share-based compensation awards.

+ References

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+ 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 (a)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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