Fair Values of Financial Instruments - Comparison of Carrying Amounts and Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
FINANCIAL ASSETS
Securities available for sale	$ 322,268	$ 330,337
Securities held to maturity	29,909	32,045
Equity securities	383	392
Loans held for investment, net	441,768	416,753
Loan servicing rights	5,240	5,078
Accrued interest receivable	2,731	2,554
FINANCIAL LIABILITIES
Long-term debt	29,549	29,530
Carrying Value [Member]
FINANCIAL ASSETS
Cash and cash equivalents	115,710	94,410
Securities available for sale	322,268	330,337
Securities held to maturity	30,722	30,801
Equity securities	383	392
Loans held for investment, net	441,768	416,753
Loans held for sale	11,910	21,684
Restricted stock	1,428	921
Loan servicing rights	5,240	5,078
Mortgage banking derivatives	1,485	1,269
Accrued interest receivable	2,731	2,554
FINANCIAL LIABILITIES
Deposits	883,498	836,752
Short-term borrowings	1,344	1,081
Long-term debt	29,549	29,530
Mortgage banking derivatives		50
Accrued interest payable	68	7
Estimated Fair Value [Member]
FINANCIAL ASSETS
Cash and cash equivalents	115,710	94,357
Securities available for sale	322,268	330,337
Securities held to maturity	29,909	32,045
Equity securities	383	392
Loans held for investment, net	431,121	412,585
Loans held for sale	11,910	21,684
Restricted stock	1,428	921
Loan servicing rights	6,239	5,509
Mortgage banking derivatives	1,485	1,269
Accrued interest receivable	2,731	2,554
FINANCIAL LIABILITIES
Deposits	882,711	836,567
Short-term borrowings	1,344	1,081
Long-term debt	28,248	30,039
Mortgage banking derivatives		50
Accrued interest payable	68	7
Level 1 [Member]
FINANCIAL ASSETS
Cash and cash equivalents	115,710	90,924
Securities available for sale	29,389
Equity securities	383	392
Restricted stock	1,428	921
Level 2 [Member]
FINANCIAL ASSETS
Cash and cash equivalents		3,433
Securities available for sale	292,879	330,337
Securities held to maturity	15,370	16,898
Loans held for sale	11,910	21,684
Loan servicing rights	6,239	5,509
Mortgage banking derivatives	1,216	253
FINANCIAL LIABILITIES
Deposits	882,711	836,567
Short-term borrowings	1,344	1,081
Mortgage banking derivatives		50
Level 3 [Member]
FINANCIAL ASSETS
Securities held to maturity	14,539	15,147
Loans held for investment, net	431,121	412,585
Mortgage banking derivatives	269	1,016
Accrued interest receivable	2,731	2,554
FINANCIAL LIABILITIES
Long-term debt	28,248	30,039
Accrued interest payable	$ 68	$ 7