Loans Receivable and Allowance for Credit Losses - Collateral, Sales, Serviced for Others, Directors and Executive Officers (Details)	12 Months Ended	24 Months Ended
Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) loan	Dec. 31, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable
Loans serviced for others	$ 33,200,000	$ 36,000,000.0	$ 33,200,000
Loans serviced for others, securitization for which the company continues to hold the related mortgage-backed securities	19,300,000	20,700,000	$ 19,300,000
Loans serviced for others, amount of contractually specified servicing fees earned	91,000	101,000
Contractually Specified Servicing Fee Income, Statement of Income or Comprehensive Income [Extensible Enumeration]			Loan And Deposit Services, Fees And Commissions
Loans to directors and executive officers	$ 392,000	414,000	$ 392,000
Mortgage Loans on Real Estate \| Maximum
Accounts, Notes, Loans and Financing Receivable
Loan to value ratio (as a percent)	80.00%		80.00%
Residential Mortgage Loans Held For Sale
Accounts, Notes, Loans and Financing Receivable
Residential mortgage loans sold, loan amount	$ 827,000	5,400,000
Residential mortgage loans sold, recognized gains		$ (3,000)
Number of nonaccrual loans \| loan		0
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable
Residential mortgage loans sold, recognized gains	$ 10,000

Represents the loan to value ratio.

No definition available.

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- Definition

Represents the number of mortgage loans outstanding.

+ 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.

+ Details

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- Definition

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481326/860-20-50-4

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- Definition

Indicates line item in statement of income or comprehensive income that includes contractually specified servicing fee income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481229/860-50-50-2

+ Details

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- Definition

All amounts that, per contract, are due to the servicer in exchange for servicing the financial asset and would no longer be received by a servicer if the beneficial owners of the serviced assets (or their trustees or agents) were to exercise their actual or potential authority under the contract to shift the servicing to another servicer. Depending on the servicing contract, those fees may include some or all of the difference between the interest rate collected on the asset being serviced and the rate to be paid to the beneficial owners of the asset.

+ References

+ Details

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- Definition

Reflects the net positive or negative amount derived from subtracting from net proceeds of sale and the carrying amounts, net of allocated reserves, of financial assets transferred to third parties in transactions that qualify for sales treatment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481326/860-20-50-5

+ Details

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- Definition

For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

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- Definition

Amount of decrease in investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate, from sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 948
-SubTopic 310
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 6))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479851/948-310-S99-1

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- Definition

This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Subparagraph (a)
-Paragraph 4
-SubTopic 20
-Topic 860
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481326/860-20-50-4

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