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Derivative Instruments Schedule of Futures (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative, Fair Value, Net	$ (18,502)	$ 2,133
Futures [Member] | Short [Member]
Derivative [Line Items]
Derivative, Notional Amount	(80,200)	(33,400)
US Treasury Note Futures [Member] | Futures [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	$ (3,369)	$ 338
Derivative, Average Remaining Maturity	2 months 21 days	2 months 22 days
US Treasury Note Futures [Member] | Futures [Member] | Long [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ (2,200)	$ (4,100)
Derivative, Fair Value, Net	$ 331	$ (96)
Derivative, Average Remaining Maturity	2 months 26 days	2 months 26 days
US Treasury Note Futures [Member] | Futures [Member] | Short [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ (82,400)	$ (37,500)
Derivative, Fair Value, Net	$ (3,700)	$ 434
Derivative, Average Remaining Maturity	2 months 26 days	2 months 22 days

X

- 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.

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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=118260190&loc=d3e13433-108611

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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

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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=109980867&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=109980867&loc=SL5579245-113959

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