INVESTMENTS IN MORTGAGE SERVICING RIGHTS AND MSR FINANCING RECEIVABLES - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019	Dec. 31, 2019		Jan. 31, 2018	Jul. 31, 2017
Schedule of MSRs [Line Items]
Residential mortgage loans subject to repurchase	$ 1,458,325	[1]	$ 168,532	$ 172,336	[1]
Residential mortgage loans, held-for-sale	4,936,826			$ 6,042,664
Reserve for non-recovery advances	18,200
Ginnie Mae Loans
Schedule of MSRs [Line Items]
Residential mortgage loans subject to repurchase	1,458,300
Residential mortgage loans, held-for-sale	491,400
Mortgage Loans Subserviced
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages	77,100,000		54,700,000
Subservicing revenue	$ 138,600		$ 99,700
Ocwen
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages						$ 86,800,000	$ 110,000,000
LoanCare
Schedule of MSRs [Line Items]
Subservicer percent of UPB	19.10%
PHH Mortgage Corporation
Schedule of MSRs [Line Items]
Subservicer percent of UPB	18.50%
Mr. Cooper
Schedule of MSRs [Line Items]
Subservicer percent of UPB	17.10%
Flagstar Bank
Schedule of MSRs [Line Items]
Subservicer percent of UPB	0.70%
NewRez
Schedule of MSRs [Line Items]
Subservicer percent of UPB	44.60%
Ocwen | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Unpaid principal balance of underlying loans, transferred	$ 66,700,000

[1] See Note 8 for details.