Loans and Allowance For Loan Losses - Summary of Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	$ 11,075	$ 10,800
Provision for loan losses	400	581
Charge offs		(137)
Recoveries	90	6
Ending balance	11,565	11,250
Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	6,708	5,578
Provision for loan losses	1,045	378
Recoveries	90	6
Ending balance	7,843	5,962
Real Estate Construction And Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	1,022	1,493
Provision for loan losses	(292)	(373)
Ending balance	730	1,120
Real Estate, Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	3,281	3,703
Provision for loan losses	(620)	448
Ending balance	2,661	4,151
Real Estate HELOC [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	6	16
Provision for loan losses	(1)	(6)
Ending balance	5	10
Installment and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning balance	58	10
Provision for loan losses	268	134
Charge offs		(137)
Ending balance	326	$ 7
Loans Receivable [Member]
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	1,297		$ 14
Collectively evaluated for impairment	10,268		11,236
Loans Receivable [Member] \| Commercial And Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	1,187		14
Collectively evaluated for impairment	6,656		5,948
Loans Receivable [Member] \| Real Estate Construction And Land [Member]
Loans and Leases Receivable Disclosure [Line Items]
Collectively evaluated for impairment	730		1,120
Loans Receivable [Member] \| Real Estate, Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Collectively evaluated for impairment	2,661		4,151
Loans Receivable [Member] \| Real Estate HELOC [Member]
Loans and Leases Receivable Disclosure [Line Items]
Collectively evaluated for impairment	5		10
Loans Receivable [Member] \| Installment and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	110
Collectively evaluated for impairment	$ 216		$ 7

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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