FAIR VALUE MEASUREMENT - Narrative (Details) $ in Millions		6 Months Ended
	Apr. 10, 2020 USD ($)	Jun. 30, 2020 USD ($) earnout_payment
Fair Value, Measurements, Nonrecurring
Schedule of Equity Method Investments [Line Items]
Assets, fair value		$ 729.5
Minimum
Schedule of Equity Method Investments [Line Items]
Broker price discount		10.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Broker price discount		25.00%
Weighted Average
Schedule of Equity Method Investments [Line Items]
Broker price discount		16.00%
Residential Mortgage Loans, Held-for-Sale | Fair Value, Measurements, Nonrecurring
Schedule of Equity Method Investments [Line Items]
Assets, fair value		$ 687.1
Real Estate Acquired in Satisfaction of Debt | Fair Value, Measurements, Nonrecurring
Schedule of Equity Method Investments [Line Items]
Assets, fair value		42.4
Loans Held-for-sale and Held-for-investment
Schedule of Equity Method Investments [Line Items]
Asset fair value adjustment		92.7
Real Estate Owned
Schedule of Equity Method Investments [Line Items]
Asset fair value adjustment		$ 1.4
Mortgage Servicing Rights Financing Receivable
Schedule of Equity Method Investments [Line Items]
Discount rate		9.50%
Mortgage Servicing Rights Financing Receivable | Minimum
Schedule of Equity Method Investments [Line Items]
Discount rate		7.90%
Mortgage Servicing Rights Financing Receivable | Maximum
Schedule of Equity Method Investments [Line Items]
Discount rate		10.00%
Mortgage Servicing Rights Financing Receivable | Weighted Average
Schedule of Equity Method Investments [Line Items]
Discount rate		9.50%
MSRs
Schedule of Equity Method Investments [Line Items]
Discount rate		8.20%
MSRs | Minimum
Schedule of Equity Method Investments [Line Items]
Discount rate		7.80%
MSRs | Maximum
Schedule of Equity Method Investments [Line Items]
Discount rate		13.50%
MSRs | Weighted Average
Schedule of Equity Method Investments [Line Items]
Discount rate		8.20%
MSRs | Excess MSRs Investees
Schedule of Equity Method Investments [Line Items]
Discount rate		8.30%
MSRs | Excess MSRs Investees | Minimum
Schedule of Equity Method Investments [Line Items]
Discount rate		8.00%
MSRs | Excess MSRs Investees | Maximum
Schedule of Equity Method Investments [Line Items]
Discount rate		8.50%
MSRs | Excess MSRs Investees | Weighted Average
Schedule of Equity Method Investments [Line Items]
Discount rate		8.30%
London Interbank Offered Rate (LIBOR) | Mortgage Servicing Rights Financing Receivable
Schedule of Equity Method Investments [Line Items]
Variable interest rate spread		2.10%
Guardian Asset Management
Schedule of Equity Method Investments [Line Items]
Cash earnout payments | earnout_payment		4
Contingent consideration, discount rate		11.00%
NRZ Guardian Purchaser LLC | Guardian Asset Management
Schedule of Equity Method Investments [Line Items]
Contingent consideration		$ 17.5
Cash consideration transferred	$ 1.9