Investment Securities Available For Sale, at Fair Value - Realized Gain or Loss Activity (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	$ 85,437	$ 432,585	$ 1,820,194
Realized Gains	18,375	16,006	19,679
Realized Losses	(31)	(4,786)	(81,208)
Net Realized Gains (Losses)	18,344	11,220	(61,529)
Total Agency
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds			1,138,377
Realized Gains			11,068
Realized Losses			(16,063)
Net Realized Gains (Losses)			(4,995)
Agency RMBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds		123,622	992,966
Realized Gains		0	5,402
Realized Losses		(3,480)	(15,854)
Net Realized Gains (Losses)		(3,480)	(10,452)
Agency RMBS \| Agency ARMs
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds			49,892
Realized Gains			44
Realized Losses			(4,157)
Net Realized Gains (Losses)			(4,113)
Agency RMBS \| Agency Fixed Rate
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds			943,074
Realized Gains			5,358
Realized Losses			(11,697)
Net Realized Gains (Losses)			(6,339)
Agency CMBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds			145,411
Realized Gains			5,666
Realized Losses			(209)
Net Realized Gains (Losses)			5,457
Non-Agency RMBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	24,374	176,166	433,076
Realized Gains	374	4,923	435
Realized Losses	0	(854)	(34,856)
Net Realized Gains (Losses)	374	4,069	(34,421)
CMBS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds		132,797	248,741
Realized Gains		11,083	8,176
Realized Losses		(452)	(30,289)
Net Realized Gains (Losses)		$ 10,631	$ (22,113)
ABS
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	36,215
Realized Gains	18,001
Realized Losses	0
Net Realized Gains (Losses)	18,001
U.S. Treasury Securities
Debt Securities, Available-for-sale [Line Items]
Sales Proceeds	24,848
Realized Gains	0
Realized Losses	(31)
Net Realized Gains (Losses)	$ (31)

Proceeds Including Receivable For Unsettled Trades From Sale Of Debt Securities, Available-For-Sale

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27357-111563

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27357-111563

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

+ References

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+ References

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