Note 4 - Earnings Per Common Share (EPS) - Summary of Calculation of Diluted EPS (Details) - shares	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Weighted average common shares outstanding (in shares)	1,978,926	1,983,553	1,981,568	1,983,553
Dilutive effect of stock options (in shares)
Weighted average common and common equivalent shares outstanding (in shares)	1,978,926	1,983,553	1,981,568	1,983,553

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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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.

+ References

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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