EXCESS MORTGAGE SERVICING RIGHTS - Summary of Direct Investments in Excess MSRs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Weighted Average Life (Years)			1 year 2 months 12 days
Agency
Schedule of Equity Method Investments [Line Items]
Original and Recaptured Pools	$ (599)	$ 1,066	$ (10,417)	$ (1,564)
Servicer advance investments | Servicer Advances
Schedule of Equity Method Investments [Line Items]
Residential mortgage loan UPB and other collateral	16,235,846		16,235,846		$ 17,033,753
Excess MSRs
Schedule of Equity Method Investments [Line Items]
Residential mortgage loan UPB and other collateral	46,130,066		$ 46,130,066
Weighted Average Life (Years)			6 years 3 months 18 days
Amortized Cost Basis	193,154		$ 193,154
Carrying Value	$ 224,632		$ 224,632		$ 249,366
Excess MSRs | Minimum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	32500.00%		32500.00%
Excess MSRs | Maximum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	100.00%		100.00%
Excess MSRs | Weighted Average
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	56500.00%		56500.00%
Excess MSRs | Former Manager-managed funds | Minimum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	0.00%		0.00%
Excess MSRs | Former Manager-managed funds | Maximum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	50.00%		50.00%
Excess MSRs | Mr. Cooper | Minimum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	0.00%		0.00%
Excess MSRs | Mr. Cooper | Maximum
Schedule of Equity Method Investments [Line Items]
Interest in Excess MSR	35.00%		35.00%