Securities, at Fair Value (Residential Mortgage Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 350,115	$ 399,999
Residential Mortgage Securities
Debt Securities, Available-for-sale [Line Items]
Principal/ Current Face	105,487	161,878
Purchase Premiums	3,764	3,022
Accretable Purchase Discounts	(69)	(8,206)
Discount Designated as Credit Reserve and OTTI	(20,768)	(21,437)
Amortized Cost	88,414	135,257
Gross Unrealized Gains	17,207	26,926
Gross Unrealized Losses	(206)	(1,183)
Net Unrealized Gain/(Loss)	17,001	25,743
Fair Value	105,415	161,000
RPL/NPL MBS
Debt Securities, Available-for-sale [Line Items]
Principal/ Current Face	1,600	55,000
Amortized Cost	1,600	46,900
Fair Value	$ 1,600	$ 53,900
Expected to Recover Less Than Par
Debt Securities, Available-for-sale [Line Items]
Percentage of current face amount of Non-Agency MBS to be recovered	100.00%	99.00%
CRT, Fair Value Option
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Gains	$ 535	$ 551
Gross Unrealized Losses	(206)	(322)
Fair Value	$ 66,200	$ 66,200

Represents the amount of unamortized accretable purchase discounts related to available-for-sale securities.

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Represent the amount of purchase discount designated as credit reserves and not expected to be accreted into interest income. Also includes other than temporary impairments which are not expected to be accreted into interest income.

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Represents the amount of unamortized purchase premiums related to available-for-sale securities.

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Represents the percentage of current face amount of non-agency MBS expected to be recovered.

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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For investments which are quantified by principal amount, the principle balance held at close of period.

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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.

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