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Derivative Financial Instruments - Schedule of Notional Amount and Fair Value of Derivative Instruments Included on Company's Consolidated Balance Sheets on a net Basis (Details) - Derivatives Designated as Hedging Instruments [Member] - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
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Sep. 30, 2021 | Dec. 31, 2020
Derivatives Fair Value [Line Items] |  |  |
Estimated Fair Value Gain (Loss) | $ (1,513) | $ (2,610) |
Fair Value Hedging [Member] |  |  |
Derivatives Fair Value [Line Items] |  |  |
Estimated Fair Value Gain (Loss) | (485) | (837) |
Fair Value Hedging [Member] | Interest Rate Swaps Related to Fixed Rate Commercial Real Estate Loans [Member] |  |  |
Derivatives Fair Value [Line Items] |  |  |
Notional Amount | 20,000 | 20,000 | [1]
Estimated Fair Value Gain (Loss) | (485) | (837) |
Cash Flow Hedging [Member] |  |  |
Derivatives Fair Value [Line Items] |  |  |
Estimated Fair Value Gain (Loss) | (1,028) | (1,773) |
Cash Flow Hedging [Member] | Interest Rate Swaps Related to Variable-Rate Money Market Deposit Accounts [Member] |  |  |
Derivatives Fair Value [Line Items] |  |  |
Notional Amount | 20,000 | 20,000 | [1]
Estimated Fair Value Gain (Loss) | (775) | (1,337) |
Cash Flow Hedging [Member] | Interest Rate Swaps Related to FHLB Advances [Member] |  |  |
Derivatives Fair Value [Line Items] |  |  |
Notional Amount | 10,000 | 10,000 | [1]
Estimated Fair Value Gain (Loss) | $ (253) | $ (436) |
[1] | Derivatives in a gain position are recorded as other assets and derivatives in a loss position are recorded as other liabilities in the consolidated balance sheets

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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959 + Details
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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
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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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