Securities, at Fair Value - Sales of Residential Mortgage Securities (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	$ 15,660	$ 0	$ 3,774,556
Gains/(Losses)	84	0	90,408
Agency MBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	0	0	1,500,875
Gains/(Losses)	0	0	(19,291)
Non-Agency MBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	0	0	1,318,958
Gains/(Losses)	0	0	107,999
CRT securities
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	15,660	0	243,025
Gains/(Losses)	84	0	(27,011)
MSR-related assets
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	0	0	711,698
Gains/(Losses)	$ 0	$ 0	$ 28,711

Net gain (loss) resulting from the sales of securitized, pay-through debt securities collateralized by real estate mortgage loans (mortgages).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13(h))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

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- Definition

Amount of cash inflow from sale of investment in mortgage-backed security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3179-108585

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- Definition

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+ References

No definition available.

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