Allowances for Loan Losses - Summary of Portfolio of Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	$ 514	$ 103
Commercial and industrial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	0	0
Construction and land development [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	0	0
Real estate - commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	250	0
Real estate - residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	261	100
Real estate - home equity [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	0	0
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	$ 3	$ 3