FAIR VALUE MEASUREMENTS - Loan Securitizations (Details) $ in Thousands	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Residential Mortgage Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments at Fair Value	$ 3,051,688	$ 2,791,027
Unsecured notes, net of issuance costs	2,608,079	2,369,934
Residential Transitional Lending
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments at Fair Value	958,789	962,192
Unsecured notes, net of issuance costs	$ 866,526	$ 859,023
Residential Transitional Lending | Discount Rate | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.015	0.017
Residential Transitional Lending | Discount Rate | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.114	0.117
Residential Transitional Lending | Discount Rate | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.022	0.022
Residential Transitional Lending | Prepayment Rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.080	0.080
Residential Transitional Lending | CDR | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.008	0.008
Residential Transitional Lending | CDR | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.020	0.020
Residential Transitional Lending | CDR | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.013	0.013
Residential Transitional Lending | Loss Severity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Measurement input	0.100	0.100