Fair Value of Financial Instruments - Level 3 Assets (Details) - Recurring basis - Level 3 - Residential whole loans, at fair value - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 6,441,964	$ 5,252,047	$ 5,676,430	$ 4,222,584
Purchases and originations	635,646	591,184	1,707,209	2,379,428
Draws	166,937	106,633	418,928	250,455
Changes in fair value recorded in Net gain/(loss) on residential whole loans measured at fair value through earnings	(129,661)	(241,093)	(131,856)	(623,012)
Repayments	(309,214)	(236,236)	(836,440)	(718,983)
Loan sales	(2,243)	0	(3,720)	(10,496)
Transfer to REO	(10,007)	(9,565)	(37,129)	(37,006)
Balance at end of period	$ 6,793,422	$ 5,462,970	$ 6,793,422	$ 5,462,970

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Originations And Draws

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- Definition

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Collection Of Principal

+ References

No definition available.

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- Definition

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Repurchases

+ References

No definition available.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

+ References

No definition available.

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-SubTopic 10
-Topic 820
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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