Loans - Summary of Information Regarding Impaired Loans (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 31	$ 97
Recorded Investment	1,492	2,377
Unpaid Principal	31	97
Principal Balance	1,843	2,693
Reserve	31	12
Average Investment	86	278
Average Investment	2,224	2,552
Interest Recognized		3
Interest Recognized	30	70
Recorded Investment	1,461	2,280
Principal Balance	1,812	2,596
Related Allowance	31	12
Average Investment	2,138	2,274
Interest Recognized	30	67
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	140	701
Principal Balance	140	701
Average Investment	585	658
Interest Recognized	15	40
Commercial Land Development [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		303
Principal Balance		303
Average Investment	253	303
Commercial Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	246	161
Principal Balance	254	161
Average Investment	210	46
Interest Recognized	6	2
Residential real estate and consumer First mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment		91
Unpaid Principal		91
Reserve		6
Average Investment	76	154
Interest Recognized		3
Recorded Investment	1,046	1,085
Principal Balance	1,362	1,375
Average Investment	1,060	1,235
Interest Recognized	9	25
Consumer Home Equity and Lines of Credit [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	31	6
Unpaid Principal	31	6
Reserve	31	6
Average Investment	10	124
Recorded Investment	29	30
Principal Balance	56	56
Average Investment	$ 30	$ 32

Impaired financing receivable with no related allowance.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of allowance for credit losses related to recorded investment.

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