FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value Measurement Inputs (Details) - Valuation Technique, Discounted Cash Flow	Sep. 30, 2023	Dec. 31, 2022
Minimum | SBA 7(a) loans receivable, subject to credit risk | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.0880	0.1100
Minimum | SBA 7(a) loans receivable, subject to credit risk | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.0488	0.0500
Minimum | SBA 7(a) loans receivable, subject to loan-backed notes | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1025
Minimum | SBA 7(a) loans receivable, subject to loan-backed notes | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.0488
Minimum | SBA 7(a) loans receivable, subject to secured borrowings | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1125	0.1100
Minimum | SBA 7(a) loans receivable, subject to secured borrowings | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.0500	0.0500
Maximum | SBA 7(a) loans receivable, subject to credit risk | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1200	0.1125
Maximum | SBA 7(a) loans receivable, subject to credit risk | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1750	0.1700
Maximum | SBA 7(a) loans receivable, subject to loan-backed notes | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1200
Maximum | SBA 7(a) loans receivable, subject to loan-backed notes | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1750
Maximum | SBA 7(a) loans receivable, subject to secured borrowings | Measurement Input, Discount Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1175	0.1125
Maximum | SBA 7(a) loans receivable, subject to secured borrowings | Measurement Input, Prepayment Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input for loans receivable	0.1750	0.1700