FAIR VALUE MEASUREMENTS - Schedule of Inputs Used In Valuing Residential Mortgage Loans, Consumer Loans, Mortgage Loans Receivable, Derivatives, and Mortgage Backed Securities (Details) $ in Thousands	Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Residential mortgage loans, HFI, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, fair value	$ 354,003	$ 361,890
Residential mortgage loans, HFI, at fair value | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.070	0.079
Residential mortgage loans, HFI, at fair value | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.092	0.093
Residential mortgage loans, HFI, at fair value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.080	0.084
Residential mortgage loans, HFI, at fair value | Prepayment Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.045	0.054
Residential mortgage loans, HFI, at fair value | Prepayment Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.090	0.082
Residential mortgage loans, HFI, at fair value | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.081	0.080
Residential mortgage loans, HFI, at fair value | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.014	0.013
Residential mortgage loans, HFI, at fair value | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.105	0.049
Residential mortgage loans, HFI, at fair value | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.031	0.033
Residential mortgage loans, HFI, at fair value | Loss Severity | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.210	0.124
Residential mortgage loans, HFI, at fair value | Loss Severity | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.312	0.337
Residential mortgage loans, HFI, at fair value | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.264	0.264
Consumer Loans HFI, at Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	$ 554,168	$ 665,565
Consumer Loans HFI, at Fair Value | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	201,468	219,308
Consumer Loans HFI, at Fair Value | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	$ 352,700	$ 446,257
Consumer Loans HFI, at Fair Value | Discount Rate | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.092	0.092
Consumer Loans HFI, at Fair Value | Discount Rate | Minimum | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.074	0.079
Consumer Loans HFI, at Fair Value | Discount Rate | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.102	0.102
Consumer Loans HFI, at Fair Value | Discount Rate | Maximum | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.175	0.179
Consumer Loans HFI, at Fair Value | Discount Rate | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.094	0.094
Consumer Loans HFI, at Fair Value | Discount Rate | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.103	0.101
Consumer Loans HFI, at Fair Value | Prepayment Rate | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.134	0.129
Consumer Loans HFI, at Fair Value | Prepayment Rate | Minimum | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.000	0.000
Consumer Loans HFI, at Fair Value | Prepayment Rate | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.390	0.384
Consumer Loans HFI, at Fair Value | Prepayment Rate | Maximum | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.220	0.231
Consumer Loans HFI, at Fair Value | Prepayment Rate | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.151	0.145
Consumer Loans HFI, at Fair Value | Prepayment Rate | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.156	0.178
Consumer Loans HFI, at Fair Value | CDR | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.028	0.023
Consumer Loans HFI, at Fair Value | CDR | Minimum | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.030	0.040
Consumer Loans HFI, at Fair Value | CDR | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.428	0.171
Consumer Loans HFI, at Fair Value | CDR | Maximum | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.620	0.500
Consumer Loans HFI, at Fair Value | CDR | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.051	0.051
Consumer Loans HFI, at Fair Value | CDR | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.196	0.143
Consumer Loans HFI, at Fair Value | Loss Severity | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.718	0.742
Consumer Loans HFI, at Fair Value | Loss Severity | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	1.000	1.000
Consumer Loans HFI, at Fair Value | Loss Severity | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.927	0.923
Consumer Loans HFI, at Fair Value | Loss Severity | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.875	0.875
IRLCs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, fair value	$ 34,387	$ 11,294
IRLCs | Loan Funding Probability | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.000	0.000
IRLCs | Loan Funding Probability | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	1.000	1.000
IRLCs | Loan Funding Probability | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.830	0.861
IRLCs | Fair Value of Initial Servicing Rights (bps) | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.00019	0.00010
IRLCs | Fair Value of Initial Servicing Rights (bps) | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.04238	0.04267
IRLCs | Fair Value of Initial Servicing Rights (bps) | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.02728	0.02818
Asset-Backed Securities Issued
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, fair value	$ 169,035	$ 185,460
Asset-Backed Securities Issued | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.059	0.054
Asset-Backed Securities Issued | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.151	0.145
Asset-Backed Securities Issued | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.051	0.051
Asset-Backed Securities Issued | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.927	0.923
Performing Financial Instruments | Residential Transition Loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held For investment, fair value	$ 2,287,856	$ 2,128,801
Performing Financial Instruments | Residential Transition Loans | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.083	0.083
Performing Financial Instruments | Residential Transition Loans | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.095	0.099
Performing Financial Instruments | Residential Transition Loans | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.083	0.083
Performing Financial Instruments | Residential Transition Loans | Prepayment Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.000	0.000
Performing Financial Instruments | Residential Transition Loans | Prepayment Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.500	0.500
Performing Financial Instruments | Residential Transition Loans | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.459	0.458
Performing Financial Instruments | Residential Transition Loans | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.005	0.005
Performing Financial Instruments | Residential Transition Loans | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.018	0.018
Performing Financial Instruments | Residential Transition Loans | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.005	0.005
Performing Financial Instruments | Residential Transition Loans | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held-for-investment, measurement input	0.250	0.250
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 17,775	$ 17,700
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.070	0.070
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.085	0.086
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.074	0.079
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Prepayment Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.054	0.060
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Prepayment Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.090	0.082
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.081	0.079
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.014	0.018
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.057	0.050
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.033	0.031
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Loss Severity | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.217	0.206
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Loss Severity | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.312	0.337
Performing Financial Instruments | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.247	0.240
Non-performing loans | Residential Transition Loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage loans, held For investment, fair value	$ 54,300	$ 55,200
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 8,658	$ 9,466
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.092	0.085
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.095	0.093
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.094	0.088
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.105	0.013
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.177	0.051
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.152	0.038
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Annual Change in Home Prices | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.055	0.086
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Annual Change in Home Prices | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.087	0.158
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Annual Change in Home Prices | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.067	0.109
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Current Value of Underlying Properties | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	2.812	2.649
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Current Value of Underlying Properties | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	3.083	3.103
Non-performing loans | Acquired loans | Residential Mortgage Loans HFS, at Fair Value | Current Value of Underlying Properties | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	2.907	2.795