Financial Instruments With Off-Balance Sheet Risk - Summary of Outstanding Contract Amounts of Off Balance Sheet Credit Risk Related Financial Instruments (Detail) - Unfunded Loan Commitment [Member] - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	$ 105,708	$ 65,143
Home equity loans [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	17,278	17,483
Commercial real estate, construction, and land development [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	15,217	10,252
Commercial and industrial [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	50,403	33,471
Other [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	$ 22,810	$ 3,937