Allowances for Loan Losses - Summary of Portfolio of Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	$ 1,246	$ 634
Commercial Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	37	39
Commercial Real Estate Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	143	144
Residential Real Estate Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	1,062	449
Consumer Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing receivable, nonaccrual	$ 4	$ 2

Amount of financing receivable on nonaccrual status.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (2)

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant