Financing Agreements - Pledged Collateral (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	$ 10,002,392	$ 9,710,754
Accrued interest	31,800	36,400
Securitized \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	6,322,900	5,730,063
Non-Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	853,645	1,513,904
Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	2,825,847	2,466,787
Residential whole loans \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	8,942,508	8,944,307
Residential whole loans \| Securitized \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	6,313,277	5,696,729
Residential whole loans \| Non-Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	853,645	1,513,904
Residential whole loans \| Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	1,775,586	1,733,674
Securities, at fair value \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	982,665	689,818
Securities, at fair value \| Securitized \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	0	0
Securities, at fair value \| Non-Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	0	0
Securities, at fair value \| Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	982,665	689,818
Other assets: REO \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	77,219	76,629
Other assets: REO \| Securitized \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	9,623	33,334
Other assets: REO \| Non-Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	0	0
Other assets: REO \| Mark-to-Market \| Asset Pledged as Collateral with Right
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	67,596	43,295
Non-agency MBS \| Mark-to-Market
Debt Instrument [Line Items]
Fair value of securities pledged as collateral under financing agreements	521,200	465,600
Securities Sold under Agreements to Repurchase	$ 394,700	$ 327,200

Accrued Interest, Securities Sold Under Agreements To Repurchase

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