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Schedule of Derivative Activity (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Interest Rate Swap [Member]
Derivative [Line Items]
Financial derivative average monthly notional	$ 596,159	$ 549,907
TBA securities [Member]
Derivative [Line Items]
Financial derivative average monthly notional	624,974	796,813
Futures [Member]
Derivative [Line Items]
Financial derivative average monthly notional	231,870	30,092
Swaption [Member]
Derivative [Line Items]
Financial derivative average monthly notional	$ 7,000	$ 4,615

X

- Definition

Average notional for the period using absolute value of month end notional amounts.

+ References

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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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- Details

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X

- Details

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- Details

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- Details

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