MORTGAGE SERVICING RIGHTS AND MSR FINANCING RECEIVABLES - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021		Jun. 30, 2020	Dec. 31, 2020		Jan. 31, 2018	Jul. 31, 2017
Schedule of MSRs [Line Items]
Residential mortgage loans subject to repurchase	$ 1,308,242	[1]	$ 1,075,008	$ 1,452,005	[1]
Residential mortgage loans, held-for-sale	7,088,441			5,215,703
Reserve for non-recovery advances	8,500			$ 22,900
Ginnie Mae Loans
Schedule of MSRs [Line Items]
Residential mortgage loans subject to repurchase	1,300,000
Residential mortgage loans, held-for-sale	922,600
Ocwen
Schedule of MSRs [Line Items]
Residential mortgage loan UPB						$ 86,800,000	$ 110,000,000
Mortgage Loans Subserviced
Schedule of MSRs [Line Items]
Residential mortgage loan UPB	76,400,000		75,400,000
Subservicing revenue	$ 84,200		$ 78,600
LoanCare
Schedule of MSRs [Line Items]
Subservicer percent of UPB	13.70%
PHH Mortgage Corporation
Schedule of MSRs [Line Items]
Subservicer percent of UPB	15.60%
Mr. Cooper
Schedule of MSRs [Line Items]
Subservicer percent of UPB	14.80%
Flagstar Bank
Schedule of MSRs [Line Items]
Subservicer percent of UPB	0.60%
NewRez
Schedule of MSRs [Line Items]
Subservicer percent of UPB	55.30%
Ocwen | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Unpaid principal balance of underlying loans, transferred	$ 66,700,000

[1] See Note 5 for details.