Fair Values of Financial Instruments - Comparison of Carrying Amounts and Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
FINANCIAL ASSETS
Securities available for sale	$ 331,154	$ 324,683
Securities held to maturity	26,596	27,178
Equity securities	326	292
Loans held for investment, net	511,798	495,599
Loan servicing rights	4,746	4,931
Accrued interest receivable	3,837	3,633
FINANCIAL LIABILITIES
Long-term borrowings	29,376	29,607
Carrying Value [Member]
FINANCIAL ASSETS
Cash and cash equivalents	117,378	114,581
Securities available for sale	331,154	324,683
Securities held to maturity	29,227	30,306
Equity securities	326	292
Loans held for investment, net	511,798	495,599
Loans held for sale	4,089	2,774
Restricted stock	1,468	1,428
Loan servicing rights	4,746	4,931
Mortgage banking derivatives	374
Accrued interest receivable	3,837	3,633
FINANCIAL LIABILITIES
Deposits	960,798	939,856
Short-term borrowings	982	1,044
Long-term borrowings	29,376	29,607
Mortgage banking derivatives	166	175
Accrued interest payable	70	108
Estimated Fair Value [Member]
FINANCIAL ASSETS
Cash and cash equivalents	117,378	114,581
Securities available for sale	331,154	324,683
Securities held to maturity	26,596	27,178
Equity securities	326	292
Loans held for investment, net	477,252	458,479
Loans held for sale	4,089	2,774
Restricted stock	1,468	1,428
Loan servicing rights	6,870	6,972
Mortgage banking derivatives	374
Accrued interest receivable	3,837	3,633
FINANCIAL LIABILITIES
Deposits	959,200	938,114
Short-term borrowings	982	1,044
Long-term borrowings	25,167	25,869
Mortgage banking derivatives	166	175
Accrued interest payable	70	108
Level 1 [Member]
FINANCIAL ASSETS
Cash and cash equivalents	117,378	114,581
Securities available for sale	51,352	50,630
Equity securities	326	292
Restricted stock	1,468	1,428
Level 2 [Member]
FINANCIAL ASSETS
Securities available for sale	275,796	270,054
Securities held to maturity	13,025	13,526
Loans held for sale	4,089	2,774
Loan servicing rights	6,870	6,972
Mortgage banking derivatives	10
FINANCIAL LIABILITIES
Deposits	959,200	938,114
Short-term borrowings	982	1,044
Mortgage banking derivatives	166	80
Level 3 [Member]
FINANCIAL ASSETS
Securities available for sale	4,006	3,999
Securities held to maturity	13,571	13,652
Loans held for investment, net	477,252	458,479
Mortgage banking derivatives	364
Accrued interest receivable	3,837	3,633
FINANCIAL LIABILITIES
Long-term borrowings	25,167	25,869
Mortgage banking derivatives		95
Accrued interest payable	$ 70	$ 108