SERVICER ADVANCE INVESTMENTS - Summary of Investments in Servicer Advances - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investments in and Advances to Affiliates [Line Items]
Outstanding Servicer Advances	$ 389,905	$ 398,820
Face Amount of Secured Notes and Bonds Payable	21,583,871
Servicer advance investments | Servicer Advances
Investments in and Advances to Affiliates [Line Items]
UPB of Underlying Residential Mortgage Loans	16,569,002	17,033,753
Outstanding Servicer Advances	$ 339,309	$ 341,628
Servicer Advances to UPB of Underlying Residential Mortgage Loans	2.00%	2.00%
Face Amount of Secured Notes and Bonds Payable	$ 304,688	$ 319,276
Gross Loan-to-Value	87.70%	90.20%
Net Loan-to-Value	85.60%	88.30%
Gross Cost of Funds	6.90%	6.50%
Net Cost of Funds	6.40%	5.90%