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Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions - Fair Value of Derivatives (Details) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2019 USD ($) item | Dec. 31, 2018 USD ($) item
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 | $ 256,000 |
Designated as Hedging Instrument [Member] |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |
Derivative liabilities designated as hedging instruments, fair value | $ 4,696,000 |
Designated as Hedging Instrument [Member] | Interest Rate Products |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |
Derivative, number of transactions | item | 1 | 1
Notional Amount | $ 25,774,000 |
Derivated liabilities designated as hedging instruments, classified in other liabilities | 4,696,000 |
Derivative liabilities designated as hedging instruments, fair value |  | $ 58,000
Designated as Hedging Instrument [Member] | Interest Rate Products | OSBC Affiliates |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |
Notional Amount |  | 25,800,000
Not Designated as Hedging Instrument [Member] |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |
Derivative assets not designated as hedging instruments, fair value | 4,209,000 | 831,000
Total Derivative liabilities not designated as hedging instruments, fair value | $ 3,835,000 | 698,000
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 | 24 |
Notional Amount | $ 174,531,000 | $ 188,900,000
Interest rate derivatives, derivative assets not designated as hedging instruments, classified in other assets | 3,756,000 |
Interest rate derivatives, derivative not designated as hedging instruments, classified in other liabilities | $ 3,756,000 |
Weighted average maturity | 6 years | 6 years 7 months 6 days
Not 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 | $ 176,000 | $ 260,000
Investment securities pledged with financial institutions, dollars | $ 11,300,000 | $ 0
Number of correspondent financial institutions where investment securities are pledged | item | 1 | 1
Number of financial institutions where investment securities are required to be pledged | item | 2 |
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 | 141 | 63
Notional Amount | $ 50,520,000 | $ 18,130,000
Interest rate derivatives, derivative assets not designated as hedging instruments, classified in other assets | $ 453,000 | $ 159,000
Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments and Forward Contracts | Commercial Loan Customers |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |
Derivative, number of transactions | item |  | 25
Notional Amount |  | $ 188,931,000
Interest rate derivatives, derivative assets not designated as hedging instruments, classified in other assets |  | 672,000
Interest rate derivatives, derivative not designated as hedging instruments, classified in other liabilities |  | $ 672,000
Not Designated as Hedging Instrument [Member] | Other Contracts |  |
Financial Instruments with Off-Balance Sheet Risk and Derivative Transactions |  |
Derivative, number of transactions | item | 4 | 3
Notional Amount | $ 28,231,000 | $ 18,155,000
Derivated liabilities designated as hedging instruments, classified in other liabilities |  | $ 26,000
Interest rate derivatives, derivative not designated as hedging instruments, classified in other liabilities | $ 79,000 |

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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=6876686&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=119400593&loc=d3e572229-122910 + 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=109980867&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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