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.

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

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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 exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Note 8 - Stock-Based Compensation (Details) - Stock Options Outstanding and Exercisable (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Stock options outstanding (in Shares)	468,751	757,183	502,789	501,334
Outstanding options, weighted-average exercise price	$ 10.57	$ 11.31	$ 11.18	$ 10.34
Outstanding options, weighted-average remaining contractual life	3 years 299 days
Exercisable options, stock options exercisable (in Shares)	388,721
Exercisable options, weighted-average exercise price	$ 10.59
Range 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options, exercise price range, lower limit	$ 5.76
Outstanding options, exercise price range, upper limit	$ 9.21
Stock options outstanding (in Shares)	225,479
Outstanding options, weighted-average exercise price	$ 5.76
Outstanding options, weighted-average remaining contractual life	3 years 284 days
Exercisable options, exercise price range, lower limit	$ 5.76
Exercisable options, exercise price range, upper limit	$ 9.21
Exercisable options, stock options exercisable (in Shares)	168,569
Exercisable options, weighted-average exercise price	$ 5.76
Range 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options, exercise price range, lower limit	$ 9.22
Outstanding options, exercise price range, upper limit	$ 15.47
Stock options outstanding (in Shares)	173,907
Outstanding options, weighted-average exercise price	$ 11.83
Outstanding options, weighted-average remaining contractual life	2 years 302 days
Exercisable options, exercise price range, lower limit	$ 9.22
Exercisable options, exercise price range, upper limit	$ 15.47
Exercisable options, stock options exercisable (in Shares)	166,467
Exercisable options, weighted-average exercise price	$ 11.88
Range 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options, exercise price range, lower limit	$ 15.48
Outstanding options, exercise price range, upper limit	$ 22.66
Stock options outstanding (in Shares)	37,774
Outstanding options, weighted-average exercise price	$ 19.11
Outstanding options, weighted-average remaining contractual life	8 years 105 days
Exercisable options, exercise price range, lower limit	$ 15.48
Exercisable options, exercise price range, upper limit	$ 22.66
Exercisable options, stock options exercisable (in Shares)	32,494
Exercisable options, weighted-average exercise price	$ 19.43
Range 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options, exercise price range, lower limit	$ 22.67
Outstanding options, exercise price range, upper limit	$ 32.36
Stock options outstanding (in Shares)	31,591
Outstanding options, weighted-average exercise price	$ 27.69
Outstanding options, weighted-average remaining contractual life	4 years 94 days
Exercisable options, exercise price range, lower limit	$ 22.67
Exercisable options, exercise price range, upper limit	$ 32.36
Exercisable options, stock options exercisable (in Shares)	21,191
Exercisable options, weighted-average exercise price	$ 25.40