INVESTMENTS IN MORTGAGE SERVICING RIGHTS AND MORTGAGE SERVICING RIGHTS FINANCING RECEIVABLE - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions							9 Months Ended
	Aug. 08, 2017	Jul. 23, 2017	Feb. 17, 2017	Jan. 31, 2017	Jan. 27, 2017	Dec. 28, 2016	Sep. 30, 2017	Jun. 30, 2017
Schedule of MSRs [Line Items]
Initial contract term (in years)		5 years
Contract extension term with thirty day notice (in months)		3 months
PHH Mortgage Corporation
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages								$ 6,000.0
Ocwen
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages		$ 110,000.0						110,000.0
Number of shares acquired (in shares)		6,075,510
Par value of shares acquired (in dollars per share)		$ 0.01
Share price (in dollars per share)		$ 2.29
Payments to acquire equity method investments		$ 13.9
Payments to acquire MSRs (up to)		$ 400.0
Ditech Financial LLC
Schedule of MSRs [Line Items]
Subservicer percent of UPB							29.10%
Ditech Financial LLC | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Payments to acquire MSRs							$ 54.9
Ditech Financial LLC | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages							$ 6,800.0
Nationstar
Schedule of MSRs [Line Items]
Subservicer percent of UPB							27.60%
Nationstar | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages							$ 49,900.0
PHH Mortgage Corporation
Schedule of MSRs [Line Items]
Subservicer percent of UPB							21.20%
PHH Mortgage Corporation | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Initial term, underlying loans							3 years
PHH Mortgage Corporation | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages						$ 60,500.0	$ 40,800.0	$ 13,200.0
PHH Mortgage Corporation | New Residential Mortgage LLC | Seasoned Agency Loans
Schedule of MSRs [Line Items]
Payments to acquire MSRs						502.7
PHH Mortgage Corporation | New Residential Mortgage LLC | Private-label Residential Mortgage Loans
Schedule of MSRs [Line Items]
Payments to acquire MSR, servicer advances						$ 218.2
CitiMortgage, Inc
Schedule of MSRs [Line Items]
Subservicer percent of UPB							13.80%
CitiMortgage, Inc | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Payments to acquire MSRs					$ 906.0
Purchase price holdback					45.3
CitiMortgage, Inc | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages					$ 92,500.0
Ocwen
Schedule of MSRs [Line Items]
Subservicer percent of UPB							6.40%
Ocwen | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
Payments to acquire MSRs							$ 54.6
Unpaid Principal Balance of underlying loans transferred							15,500.0
Unpaid Principal Balance of underlying loans to be transferred							$ 92,300.0
Flagstar
Schedule of MSRs [Line Items]
Subservicer percent of UPB							1.10%
United Shore Financial Services, LLC
Schedule of MSRs [Line Items]
Subservicer percent of UPB							0.80%
United Shore Financial Services, LLC | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Payments to acquire MSRs	$ 19.7			$ 94.8
Purchase price holdback	2.0			9.5
United Shore Financial Services, LLC | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages	$ 2,100.0			$ 9,800.0
Residential Credit Solutions, Inc. | New Residential Mortgage LLC
Schedule of MSRs [Line Items]
Payments to acquire MSRs			$ 48.6
Purchase price holdback			4.9
Payments to acquire MSR, servicer advances			1.3
Residential Credit Solutions, Inc. | New Residential Mortgage LLC | Mortgage Servicing Rights
Schedule of MSRs [Line Items]
UPB of Underlying Mortgages			$ 5,200.0