Earnings per share - Computation of Basic and Diluted Weighted Average Shares Outstanding (Detail) - shares	3 Months Ended	6 Months Ended
Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Earnings Per Share [Line Items]
Weighted average shares outstanding for basic earnings per share	9,356,660	9,053,838	9,332,665	8,965,672
Add effects of potentially dilutive securities-assumed exercise of stock options	481,304	332,356	505,053	279,053
Weighted average shares outstanding for diluted earnings per share	9,837,964	9,386,194	9,837,718	9,244,725

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
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- Definition

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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- Definition

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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-Topic 260
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