Loans and Leases Receivable and Allowance for Credit Losses on Loans and Leases - Summary of Loans Modified in Troubled Debt Restructurings and Related Recorded Investment (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($) Loan	Sep. 30, 2020 USD ($) Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| Loan	21	15
Recorded Investment \| $	$ 302	$ 1,374
Manufactured housing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| Loan	2	5
Recorded Investment \| $	$ 71	$ 201
Commercial real estate owner occupied
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| Loan	0	1
Recorded Investment \| $	$ 0	$ 952
Residential real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| Loan	0	1
Recorded Investment \| $	$ 0	$ 95
Installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of loans \| Loan	19	8
Recorded Investment \| $	$ 231	$ 126

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953682-111524

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Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953682-111524

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