Note 2 - Income (Loss) Per Share - Calculation of Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income	$ 4,433	$ 4,417
Denominator:
Denominator for basic income per share – weighted-average shares (in shares)	18,381	18,331
Effect of dilutive securities:
Equivalent shares issuable upon conversion of unvested restricted shares (in shares)	152	75
Diluted weighted average shares outstanding (in shares)	18,533	18,406
Income per share:
Basic and diluted income per share (in dollars per share)	$ 0.24	$ 0.24

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of equity unit purchase agreements using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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