Residential Mortgage Loans - Derivative Instruments Related to Mortgage Loan Activity (Parenthetical) (Details) - Designated as Hedging Instrument - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Forward RMBS purchase contracts
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash collateral receivable (payable)	$ 1,000	$ 715
Interest rate swap futures contracts
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash collateral receivable (payable)	$ 2,000	$ 720

Amount of receivable from positive price movement on derivative.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(3)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477802/946-310-45-1

Name:	us-gaap_VariationMarginReceivableDerivative
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant