Loans - Summary of Allowance for Loan and Lease Losses for Loans Evaluated Individually and Collectively for Impairment (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	$ 6,227	$ 11,005
Collectively evaluated for impairment	319,765	320,593
Total loans	325,992	331,598
Collectively evaluated for impairment	2,858	2,703
Total allowance for loan losses	2,858	2,703	$ 2,000
Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	4,833	10,573
Collectively evaluated for impairment	219,950	226,394
Total loans	224,783	236,967
Collectively evaluated for impairment	1,657	1,609
Total allowance for loan losses	1,657	1,609	1,235
Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	1,357	411
Collectively evaluated for impairment	82,692	71,511
Total loans	84,049	71,922
Collectively evaluated for impairment	745	745
Total allowance for loan losses	745	745	573
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Individually evaluated for impairment	37	21
Collectively evaluated for impairment	17,123	22,688
Total loans	17,160	22,709
Collectively evaluated for impairment	456	349
Total allowance for loan losses	$ 456	$ 349	$ 192