FAIR VALUE MEASUREMENTS - Information Regarding the Inputs used in Valuing the Servicer Advances (Details)	3 Months Ended
	Mar. 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value inputs, monthly servicing fee	620.00%
Servicer Advances | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Outstanding Servicer Advances to UPB of Underlying Residential Mortgage Loans	1.30%
Mortgage Servicing Amount	0.00180
Servicer Advances | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Outstanding Servicer Advances to UPB of Underlying Residential Mortgage Loans	2.20%
Mortgage Servicing Amount	0.00198
Servicer Advances | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Outstanding Servicer Advances to UPB of Underlying Residential Mortgage Loans	2.20%
Mortgage Servicing Amount	0.00198
Prepayment Rate | Servicer Advances | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.034
Prepayment Rate | Servicer Advances | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.046
Prepayment Rate | Servicer Advances | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.046
Delinquency | Servicer Advances | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.034
Delinquency | Servicer Advances | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.197
Delinquency | Servicer Advances | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.193
Discount Rate | Servicer Advances | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.057
Discount Rate | Servicer Advances | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.062
Discount Rate | Servicer Advances | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing asset, measurement input	0.057
Collateral Weighted Average Maturity (Years) | Servicer Advances | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Collateral Weighted Average Maturity (Years)	21 years 9 months 18 days
Collateral Weighted Average Maturity (Years) | Servicer Advances | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Collateral Weighted Average Maturity (Years)	21 years 10 months 24 days
Collateral Weighted Average Maturity (Years) | Servicer Advances | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Collateral Weighted Average Maturity (Years)	21 years 10 months 24 days