EXCESS MORTGAGE SERVICING RIGHTS - Summary of Direct Investments in Excess MSRs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Weighted Average Life (Years)	1 year 1 month 6 days
Agency
Schedule of Equity Method Investments [Line Items]
Original and Recaptured Pools	$ (9,818)	$ (2,630)
Servicer advance investments | Servicer Advances
Schedule of Equity Method Investments [Line Items]
Residential mortgage loan UPB and other collateral	16,569,002		$ 17,033,753
Excess MSRs
Schedule of Equity Method Investments [Line Items]
Residential mortgage loan UPB and other collateral	$ 46,813,093
Weighted Average Life (Years)	6 years 2 months 12 days
Amortized Cost Basis	$ 199,270
Carrying Value	$ 231,348		$ 249,366
Excess MSRs | Minimum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	32500.00%
Excess MSRs | Maximum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	100.00%
Excess MSRs | Weighted Average
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	56500.00%
Excess MSRs | Former Manager-managed funds | Minimum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	0.00%
Excess MSRs | Former Manager-managed funds | Maximum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	50.00%
Excess MSRs | Mr. Cooper | Minimum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	0.00%
Excess MSRs | Mr. Cooper | Maximum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	35.00%