Fair Value Measurements - Financial Assets and Liabilities Carried at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Assets:
Non-Agency RMBS, at fair value	$ 1,059,840	$ 1,064,169
Agency MBS, at fair value	656,335	519,218
Loans held for investment, at fair value	10,983,840	11,196,678
Net Amounts Offset in the Consolidated Statements of Financial Position	0	117
Liabilities
Securitized debt at fair value, collateralized by Loans held for investment	7,198,089	6,984,495
Net Amounts Offset in the Consolidated Statements of Financial Position	240	0
Fair Value, Measurements, Recurring
Assets:
Non-Agency RMBS, at fair value	1,059,840	1,064,169
Agency MBS, at fair value	656,335	519,218
Loans held for investment, at fair value	10,983,840	11,196,678
Counterparty and Cash Collateral, netting	(8,518)	(7,146)
Net Amounts Offset in the Consolidated Statements of Financial Position	0	117
Liabilities
Secured Financing Agreements, at fair value	320,730	319,456
Securitized debt at fair value, collateralized by Loans held for investment	7,198,089	6,984,495
Counterparty and Cash Collateral, netting	0	0
Net Amounts Offset in the Consolidated Statements of Financial Position	240	0
Fair Value, Measurements, Recurring | Level 1
Assets:
Non-Agency RMBS, at fair value	0	0
Agency MBS, at fair value	0	0
Loans held for investment, at fair value	0	0
Derivatives, at fair value	0	117
Liabilities
Secured Financing Agreements, at fair value	0	0
Securitized debt at fair value, collateralized by Loans held for investment	0	0
Derivatives, at fair value	0	0
Fair Value, Measurements, Recurring | Level 2
Assets:
Non-Agency RMBS, at fair value	0	0
Agency MBS, at fair value	656,335	519,218
Loans held for investment, at fair value	286,697	337,833
Derivatives, at fair value	8,518	7,146
Liabilities
Secured Financing Agreements, at fair value	320,730	319,456
Securitized debt at fair value, collateralized by Loans held for investment	0	0
Derivatives, at fair value	240	0
Fair Value, Measurements, Recurring | Level 3
Assets:
Non-Agency RMBS, at fair value	1,059,840	1,064,169
Agency MBS, at fair value	0	0
Loans held for investment, at fair value	10,697,143	10,858,845
Derivatives, at fair value	0	0
Liabilities
Secured Financing Agreements, at fair value	0	0
Securitized debt at fair value, collateralized by Loans held for investment	7,198,089	6,984,495
Derivatives, at fair value	$ 0	$ 0