Loans - Summary of Information Regarding Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 67	$ 67
Recorded Investment	7,386	8,041
Unpaid Principal	68	68
Principal Balance	7,687	8,405
Reserve	67	67
Average Investment	67	59
Average Investment	7,504	3,582
Interest Recognized	0	0
Interest Recognized	170	128
Recorded Investment	7,319	7,974
Principal Balance	7,619	8,337
Related Allowance	67	67
Average Investment	7,437	3,523
Interest Recognized	170	128
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	5,838	5,840
Principal Balance	5,838	5,840
Average Investment	5,855	1,824
Interest Recognized	67	87
Commercial Land Development [Member]
Financing Receivable, Impaired [Line Items]
Average Investment		126
Commercial Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	855	1,091
Principal Balance	855	1,091
Average Investment	835	488
Interest Recognized	17	23
Residential real estate and consumer First mortgage [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	62	62
Unpaid Principal	62	62
Reserve	62	62
Average Investment	62	43
Interest Recognized	0	0
Recorded Investment	599	1,016
Principal Balance	870	1,350
Average Investment	720	1,056
Interest Recognized	85	18
Consumer Home Equity and Lines of Credit [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment	5	5
Unpaid Principal	6	6
Reserve	5	5
Average Investment	5	16
Recorded Investment	27	27
Principal Balance	56	56
Average Investment	27	$ 29
Interest Recognized	$ 1

Impaired financing receivable with no related allowance.

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- Definition

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+ References

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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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
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- Definition

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

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-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953550-111524

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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

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