FAIR VALUE MEASUREMENTS - Schedule of Inputs Used In Valuing Residential Mortgage Loans, Consumer Loans, Derivatives, and Mortgage Backed Securities (Details) $ in Thousands	Jun. 30, 2021 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	$ 2,024,759
Residential Mortgage Loans, Held-for-Investment, at Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, fair value	$ 617,951
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	0.058
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	0.016
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	0.300
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	0.075
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	0.067
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	0.029
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	0.715
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	0.060
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	0.062
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	0.017
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	0.678
Consumer Loans Held-for-Investment, At Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	$ 592,126
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	0.075
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	0.216
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	0.046
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	0.712
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	0.097
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	0.341
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	0.236
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	0.924
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	0.075
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	0.216
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	0.046
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	0.712
IRLCs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, fair value	$ 109,390
IRLCs | Minimum | Loan Funding Probability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.000
IRLCs | Minimum | Fair Value of Initial Servicing Rights (Bps)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.00005
IRLCs | Maximum | Loan Funding Probability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	1.000
IRLCs | Maximum | Fair Value of Initial Servicing Rights (Bps)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.03123
IRLCs | Weighted Average | Loan Funding Probability
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.829
IRLCs | Weighted Average | Fair Value of Initial Servicing Rights (Bps)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.01221
Mortgage-Backed Securities Issued
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, fair value	$ 882,178
Mortgage-Backed Securities Issued | Minimum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.016
Mortgage-Backed Securities Issued | Minimum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.048
Mortgage-Backed Securities Issued | Minimum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.003
Mortgage-Backed Securities Issued | Minimum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.200
Mortgage-Backed Securities Issued | Maximum | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.044
Mortgage-Backed Securities Issued | Maximum | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.400
Mortgage-Backed Securities Issued | Maximum | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.046
Mortgage-Backed Securities Issued | Maximum | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	1.000
Mortgage-Backed Securities Issued | Weighted Average | Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.022
Mortgage-Backed Securities Issued | Weighted Average | Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.181
Mortgage-Backed Securities Issued | Weighted Average | Delinquency
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.031
Mortgage-Backed Securities Issued | Weighted Average | Loss Severity
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities, measurement input	0.708
Non-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	$ 1,931,549
Non-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	0.025
Non-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	0.020
Non-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
Non-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
Non-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	0.070
Non-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	0.250
Non-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	0.040
Non-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	0.500
Non-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	0.036
Non-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	0.143
Non-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	0.013
Non-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	0.191
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	$ 93,210
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	0.040
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	0.055
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	0.030
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	0.500