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Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions - Fair Value of Derivatives (Details) | 1 Months Ended | 12 Months Ended
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Dec. 31, 2019 USD ($) | Dec. 31, 2021 USD ($) item | Dec. 31, 2020 USD ($) item
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Loan pool hedge | $ 50,000,000 |  |
Term of interest rate risk cash flow hedge | 5 years |  |
Amount of ineffectiveness, included in net income |  | $ 0 |
Interest Rate Swap [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Notional Amount |  | 25,800,000 | $ 25,800,000
Designated as Hedging Instrument [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Derivative assets designated as hedging instruments, fair value |  | 808,000 | 2,697,000
Derivative liabilities designated as hedging instruments, fair value |  | $ 4,102,000 | $ 6,380,000
Designated as Hedging Instrument [Member] | Interest Rate Products | OSBC Affiliates |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Derivative, number of transactions | item |  | 2 | 2
Notional Amount |  | $ 75,774,000 | $ 75,774,000
Derivative assets designated as hedging instruments, fair value |  | 808,000 | 2,697,000
Derivative liabilities designated as hedging instruments, fair value |  | 4,102,000 | 6,380,000
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Cash collateral pledged with financial institutions, dollars |  |  | 17,200,000
Not Designated as Hedging Instrument [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Derivative assets designated as hedging instruments, fair value |  | 3,194,000 | 7,531,000
Derivative liabilities designated as hedging instruments, fair value |  | $ 2,707,000 | $ 6,779,000
Not Designated as Hedging Instrument [Member] | Interest Rate Products | Commercial Loan Customers |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Derivative, number of transactions | item |  | 26 | 28
Notional Amount |  | $ 165,005,000 | $ 189,126,000
Derivative assets designated as hedging instruments, fair value |  | 2,686,000 | 6,691,000
Derivative liabilities designated as hedging instruments, fair value |  | $ 2,686,000 | $ 6,691,000
Weighted average maturity |  | 3 years 10 months 24 days | 4 years 8 months 12 days
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Notional Amount |  |  | $ 189,100,000
Cash collateral pledged with financial institutions, dollars |  | $ 17,200,000 |
Investment securities pledged with financial institutions, dollars |  | $ 0 | $ 0
Number of correspondent financial institutions where investment securities are pledged |  | 1 | 1
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member] | Cash Flow Hedging |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Cash collateral pledged with financial institutions, dollars |  | $ 180,000 | $ 1,400,000
Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments and Forward Contracts. |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Derivative, number of transactions | item |  | 87 | 205
Notional Amount |  | $ 34,414,000 | $ 84,472,000
Derivative assets designated as hedging instruments, fair value |  | $ 508,000 | $ 840,000
Not Designated as Hedging Instrument [Member] | Other Contracts |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Derivative, number of transactions | item |  | 3 | 4
Notional Amount |  | $ 17,173,000 | $ 26,523,000
Derivative liabilities designated as hedging instruments, fair value |  | 21,000 | 88,000
Not Designated as Hedging Instrument [Member] | Forward Contracts [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Notional Amount |  | 20,000,000 | 46,500,000
Interest Income [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Amount to be reclassified as a reduction to interest expense during the next twelve months |  | 190,000 | $ 190,000
Interest Expense [Member] |  |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |  |
Amount to be reclassified as a reduction to interest expense during the next twelve months |  | $ 174,000 |

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- Definition Carrying amount as of the balance sheet date of cash collateral held for borrowed securities, for which the cash is restricted as to withdrawal or usage. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.1) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.(a),2) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
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- Definition Fair value of all asset derivatives designated as cash flow hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959 + Details
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- Definition Fair value of all liability derivatives designated as cash flow hedging instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959 + Details
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- Definition Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1),(2) -URI http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986 + 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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