FAIR VALUE MEASUREMENT - Schedule of Inputs Used In Valuing Residential Mortgage Loans, Consumer Loans, Derivatives, and Mortgage Backed Securities (Details) $ in Thousands	Jun. 30, 2020 USD ($)
Residential Mortgage Loans Held-for-Sale, At Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 1,105,010
Residential Mortgage Loans, Held-for-Investment, at Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, fair value	$ 750,332
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Minimum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.041
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Minimum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.020
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Minimum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.024
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Minimum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.200
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Maximum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.100
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Maximum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.200
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Maximum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.200
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Maximum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.431
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Weighted Average | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.075
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Weighted Average | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.052
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Weighted Average | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	0.029
Residential Mortgage Loans, Held-for-Investment, at Fair Value | Weighted Average | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for investment, measurement input	4.050
Consumer Loans Held-for-Investment, At Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, at fair value	$ 766,462
Consumer Loans Held-for-Investment, At Fair Value | Minimum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.085
Consumer Loans Held-for-Investment, At Fair Value | Minimum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.177
Consumer Loans Held-for-Investment, At Fair Value | Minimum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.056
Consumer Loans Held-for-Investment, At Fair Value | Minimum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.834
Consumer Loans Held-for-Investment, At Fair Value | Maximum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.107
Consumer Loans Held-for-Investment, At Fair Value | Maximum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.293
Consumer Loans Held-for-Investment, At Fair Value | Maximum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.177
Consumer Loans Held-for-Investment, At Fair Value | Maximum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.902
Consumer Loans Held-for-Investment, At Fair Value | Weighted Average | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.085
Consumer Loans Held-for-Investment, At Fair Value | Weighted Average | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.178
Consumer Loans Held-for-Investment, At Fair Value | Weighted Average | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.057
Consumer Loans Held-for-Investment, At Fair Value | Weighted Average | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.834
IRLCs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, fair value	$ 163,945
IRLCs | Minimum | Loan Funding Probability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.60
IRLCs | Minimum | Fair Value of Initial Servicing Rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.0058
IRLCs | Maximum | Loan Funding Probability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	1
IRLCs | Maximum | Fair Value of Initial Servicing Rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.0237
IRLCs | Weighted Average | Loan Funding Probability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.8114
IRLCs | Weighted Average | Fair Value of Initial Servicing Rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.008605
Mortgage-Backed Securities Issued
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, fair value	$ 258,806
Mortgage-Backed Securities Issued | Minimum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0400
Mortgage-Backed Securities Issued | Minimum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.032
Mortgage-Backed Securities Issued | Minimum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0
Mortgage-Backed Securities Issued | Minimum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.100
Mortgage-Backed Securities Issued | Maximum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.053
Mortgage-Backed Securities Issued | Maximum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.150
Mortgage-Backed Securities Issued | Maximum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0330
Mortgage-Backed Securities Issued | Maximum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.400
Mortgage-Backed Securities Issued | Weighted Average | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0490
Mortgage-Backed Securities Issued | Weighted Average | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.072
Mortgage-Backed Securities Issued | Weighted Average | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.0220
Mortgage-Backed Securities Issued | Weighted Average | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.298
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 1,075,996
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Minimum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.045
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Minimum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Minimum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.016
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Minimum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.287
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Maximum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.060
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Maximum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.150
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Maximum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.071
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Maximum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	1.000
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Weighted Average | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.048
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Weighted Average | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.059
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Weighted Average | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.068
Purchased Credit Deteriorated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Weighted Average | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.326
Originated | Residential Mortgage Loans Held-for-Sale, At Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 29,014
Originated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.060
Originated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.150
Originated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	0.016
Originated | Residential Mortgage Loans Held-for-Sale, At Fair Value | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held for sale, measurement input	1.000