Loans - Summary of Troubled Debt Restructurings (Detail) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021 USD ($) Contract	Sep. 30, 2021 USD ($) Contract	Sep. 30, 2020 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of loans restructured \| Contract	1	7	13
Pre-Modification Recorded Investment	$ 66	$ 2,734	$ 473
Post-Modification Recorded Investment	$ 66	$ 2,734	$ 473
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured \| Contract	1	4	5
Pre-Modification Recorded Investment	$ 66	$ 960	$ 181
Post-Modification Recorded Investment	$ 66	$ 960	$ 181
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured \| Contract		2	1
Pre-Modification Recorded Investment		$ 1,686	$ 80
Post-Modification Recorded Investment		$ 1,686	$ 80
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured \| Contract		1	1
Pre-Modification Recorded Investment		$ 88	$ 66
Post-Modification Recorded Investment		$ 88	$ 66
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured \| Contract			6
Pre-Modification Recorded Investment			$ 146
Post-Modification Recorded Investment			$ 146

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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