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	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
December 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, fair value	$ 379,044	$ 452,519
December 31, 2023 | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.079	0.038
December 31, 2023 | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.083	0.087
December 31, 2023 | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.081	0.085
December 31, 2023 | Prepayment Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.029	0.093
December 31, 2023 | Prepayment Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.035	0.163
December 31, 2023 | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.032	0.123
December 31, 2023 | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.014	0.001
December 31, 2023 | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.059	0.137
December 31, 2023 | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.043	0.067
December 31, 2023 | Loss Severity | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.244	0.232
December 31, 2023 | Loss Severity | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.574	0.550
December 31, 2023 | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans, held-for-investment, measurement input	0.461	0.403
Consumer loans held-for-investment, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	$ 1,274,005
Consumer loans held-for-investment, at fair value | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	285,632	$ 363,756
Consumer loans held-for-investment, at fair value | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans	$ 988,373
Consumer loans held-for-investment, at fair value | Discount Rate | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.084	0.083
Consumer loans held-for-investment, at fair value | Discount Rate | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.094	0.093
Consumer loans held-for-investment, at fair value | Discount Rate | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.086	0.086
Consumer loans held-for-investment, at fair value | Discount Rate | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.095
Consumer loans held-for-investment, at fair value | Prepayment Rate | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.097	0.068
Consumer loans held-for-investment, at fair value | Prepayment Rate | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.373	0.332
Consumer loans held-for-investment, at fair value | Prepayment Rate | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.170	0.287
Consumer loans held-for-investment, at fair value | Prepayment Rate | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.225
Consumer loans held-for-investment, at fair value | CDR | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.017	0.000
Consumer loans held-for-investment, at fair value | CDR | Maximum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.071	0.071
Consumer loans held-for-investment, at fair value | CDR | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.048	0.043
Consumer loans held-for-investment, at fair value | CDR | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.062
Consumer loans held-for-investment, at fair value | Loss Severity | Minimum | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.825	0.894
Consumer loans held-for-investment, 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 held-for-investment, at fair value | Loss Severity | Weighted Average | SpringCastle
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.933	0.947
Consumer loans held-for-investment, at fair value | Loss Severity | Weighted Average | Marcus
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Consumer loans, held-for-investment, measurement input	0.930
Mortgage Loans Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable	$ 114,366
Mortgage Loans Receivable | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable, measurement input	0.110
Mortgage Loans Receivable | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable, measurement input	0
Mortgage Loans Receivable | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable, measurement input	0.018
Mortgage Loans Receivable | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable, measurement input	0.025
Mortgage Loans Receivable | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable, measurement input	0.022
Mortgage Loans Receivable | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financing receivable, measurement input	0.250
December 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, fair value	$ 23,804	$ 8,786
December 31, 2023 | Loan Funding Probability | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.000	0.000
December 31, 2023 | Loan Funding Probability | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	1.000	1.000
December 31, 2023 | Loan Funding Probability | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.808	0.825
December 31, 2023 | Fair Value of Initial Servicing Rights (bps) | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.00070	(0.01502)
December 31, 2023 | Fair Value of Initial Servicing Rights (bps) | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.03313	0.03246
December 31, 2023 | Fair Value of Initial Servicing Rights (bps) | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative, measurement input	0.02105	0.01856
Asset-Backed Securities Issued
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, fair value	$ 235,770	$ 319,486
Asset-Backed Securities Issued | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.033
Asset-Backed Securities Issued | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.063
Asset-Backed Securities Issued | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.060	0.061
Asset-Backed Securities Issued | Prepayment Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.137
Asset-Backed Securities Issued | Prepayment Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.218
Asset-Backed Securities Issued | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.17	0.213
Asset-Backed Securities Issued | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.001
Asset-Backed Securities Issued | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.042
Asset-Backed Securities Issued | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.048	0.039
Asset-Backed Securities Issued | Loss Severity | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.440
Asset-Backed Securities Issued | Loss Severity | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input		0.947
Asset-Backed Securities Issued | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Asset-backed securities, measurement input	0.933	0.916
Originated loans | Residential mortgage loans held-for-sale, at fair value | Dealer price quotes and historical sale transactions | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.507
Originated loans | Residential mortgage loans held-for-sale, at fair value | Dealer price quotes and historical sale transactions | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	1.000
Originated loans | Residential mortgage loans held-for-sale, at fair value | Dealer price quotes and historical sale transactions | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.857
Performing | Residential mortgage loans held-for-sale, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 78,794	$ 236,452
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 45,545	$ 52,467
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.079	0.085
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.083	0.087
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.082	0.085
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Prepayment Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.020	0.093
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Prepayment Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.098	0.114
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.059	0.097
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | CDR | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.013	0.043
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | CDR | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.059	0.083
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.023	0.050
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Loss Severity | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.126	0.200
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Loss Severity | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.574	0.371
Performing | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.290	0.241
Performing | Originated loans | Residential mortgage loans held-for-sale, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 33,249	$ 183,985
Loans held-for-sale, measurement input	0.555
Performing | Originated loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.073
Performing | Originated loans | Residential mortgage loans held-for-sale, at fair value | Prepayment Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.089
Performing | Originated loans | Residential mortgage loans held-for-sale, at fair value | CDR | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.036
Performing | Originated loans | Residential mortgage loans held-for-sale, at fair value | Loss Severity | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.207
Non-performing loans | Residential mortgage loans held-for-sale, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 25,993	24,925
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 18,944	$ 20,759
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.077	0.087
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.082	0.559
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.081	0.090
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Annual change in home prices | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.035	0.332
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Annual change in home prices | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.072	0.559
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, 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	0.059	0.407
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Liquidation Timeline (in years) | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, term	5 years 6 months	2 years 2 months 12 days
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Liquidation Timeline (in years) | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, term	11 years	3 years 9 months 18 days
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Liquidation Timeline (in years) | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, term	6 years 6 months	2 years 9 months 18 days
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Current Value of Underlying Properties | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	2.357	1.916
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, at fair value | Current Value of Underlying Properties | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	8.960	2.606
Non-performing loans | Acquired loans | Residential mortgage loans held-for-sale, 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	2.970	2.145
Non-performing loans | Originated loans | Residential mortgage loans held-for-sale, at fair value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, fair value	$ 7,049	$ 4,166
Loans held-for-sale, measurement input	0.706
Non-performing loans | Originated loans | Residential mortgage loans held-for-sale, at fair value | Discount Rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, measurement input	0.073
Non-performing loans | Originated loans | Residential mortgage loans held-for-sale, at fair value | Liquidation Timeline (in years) | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale, term	7 years 7 months 6 days