Principal-Only Stripped Mortgage-Backed Securities - Activity in the Company's investment in principal-only stripped MBS (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Mortgage-backed securities
Balance at beginning of quarter			$ 825,865
Balance at end of quarter	$ 774,021		774,021
Principal-Only-Strip MBS
Mortgage-backed securities
Balance at beginning of quarter	784,958	$ 914,223	825,865
Purchases		0		$ 935,356
Repayments	(34,991)	(23,054)	(119,258)	(36,506)
Amortization of purchase discounts	13,642	20,129	31,676	29,219
Valuation adjustments	10,412	48,969	35,738	32,198
Total	(24,054)	(69,098)	(67,414)	(61,417)
Balance at end of quarter	$ 774,021	$ 960,267	$ 774,021	$ 960,267

Amount of mortgage-backed asset securities measured at fair value pledged to creditors.

No definition available.

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- Definition

The amortization purchase discounts of mortgage-backed securities, measured at fair valued, pledged to creditors.

+ References

No definition available.

+ Details

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- Definition

The amount of fair value changes in mortgage-backed securities, measured at fair valued, pledged to creditors.

+ References

No definition available.

+ Details

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- Definition

The value of mortgage-backed asset securities, subsequently measured at fair value pledged to creditors, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

No definition available.

+ Details

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- Definition

The amount of repayment of mortgage-backed securities, measured at fair valued, pledged to creditors.

+ References

No definition available.

+ Details

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- Definition

Amount of gain (loss) from change in value adjustments of mortgage-backed asset securities.

+ References

No definition available.

+ Details

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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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