Allowance for credit losses change in method of calculating troubled debt restructuring.

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- Definition

Troubled debt restructuring interest rate concession period.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

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

+ References

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- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ 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=121611835&loc=SL6953676-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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- Definition

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=121611835&loc=SL6953682-111524

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- Definition

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=121611835&loc=SL6953682-111524

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- Definition

Amount of unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18794-111554

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Loans and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($) Contract TDR	Mar. 31, 2020 USD ($) TDR	Dec. 31, 2020 USD ($) Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans, additional funds committed	$ 0
Loans subject to troubled debt restructurings \| TDR	0	0
Allowances related to troubled debt restructurings	$ 0	$ 0
Number of Contracts \| Contract	18		18
Total TDRs	$ 2,870,000		$ 2,915,000
30 - 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings defaulted over 30 days past due	$ 0	$ 0
Residential Real Estate [Member] \| Payment Deferral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts \| TDR	2
Residential Real Estate [Member] \| Performing Financial Instruments [Member] \| Payment Deferral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total TDRs	$ 297,000
Residential Real Estate [Member] \| Nonperforming Financial Instruments [Member] \| Payment Deferral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total TDRs	$ 196,000
Residential Real Estate [Member] \| Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, interest rate concession period	3 months
Residential Real Estate [Member] \| Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, interest rate concession period	30 years
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Contracts \| Contract	1		1
Total TDRs	$ 17,000		$ 40,000
Commercial Real Estate Loans [Member] \| Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, interest rate concession period	1 year