Reconciliation of Weighted Average Shares for Basic and Diluted Earnings Per Share (Detail) - shares	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Weighted average shares for basic earnings per share	14,202,859	14,100,180	14,181,530	14,082,698
Weighted average shares for diluted earnings per share	14,327,757	14,346,585	14,328,861	14,321,113
Restricted Stock
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock, units and options	23,059	83,882	19,201	74,768
Restricted Stock Units
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock, units and options	0	0	2,954	0
Stock Options
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock, units and options	101,839	162,523	125,176	163,647

Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]

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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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 28A
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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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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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-Topic 260
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