Loans - Summary of Loans Held for Investment (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	$ 671,666	$ 647,572
Less: Unearned income	(731)	(738)
Total	670,935	646,834
Commercial and Industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	82,177	77,282
Agricultural [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	309	446
Construction, Commercial [Member] \| Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	42,527	38,039
Construction, Residential [Member] \| Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	27,152	26,778
Mortgage, Commercial [Member] \| Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	256,543	251,824
Mortgage, Residential [Member] \| Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	215,155	208,494
Mortgage, Farmland [Member] \| Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	5,394	5,507
Consumer Installment Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Gross loans	$ 42,409	$ 39,202

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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