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Derivative Instruments Schedule of Swaptions (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Sep. 30, 2018
Derivative [Line Items] |  |
Derivative, Fair Value, Net | $ 6,929 | $ 22,716
Interest Rate Swaption [Member] | Fixed Payer Swaption [Member] |  |
Derivative [Line Items] |  |
Derivative, Fair Value, Net | 181 |
Derivative notional | $ 10,000 |
Maturity term of asset underlying derivative contract | 10 years |
Derivative, Average Remaining Maturity | 7 months |
Derivative, Swaption Interest Rate | 2.40% |

X
- Definition Term to maturity of the reference asset underlying the derivative contract. + References No definition available. + Details
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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + 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 Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611 + 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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- Definition Fixed interest rate that will be received or paid upon exercise of the interest rate swaption contract. + References No definition available. + Details
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- Details
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- Details
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