Fair Value Measurement - Narrative (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans on non-accrual status	120 days
Charges-off loans	120 days
Notes receivable and residual certificates	$ 3,900,000
Average effect of fair value of hypothetical 20% adverse change in expected credit loss rates	33.00%
Beneficial interests (at fair value)	$ 28,664,000	$ 0
Fair Value, Inputs, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans held-for-sale	689,900,000	882,800,000
Loans held-for-investment	147,700,000	127,600,000
Notes receivable and residual certificates	3,907,000	$ 6,181,000
Beneficial interests (at fair value)	$ 28,664,000
Fair Value, Inputs, Level 3 | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average effect on fair value of a 100 basis point increase in discount rates	0.99%	1.10%
Average effect on fair value of a 200 basis point increase in discount rates	1.96%	2.18%
Fair Value, Inputs, Level 3 | Minimum | Discount rate | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trailing fees liability, measurement input	9.87%
Fair Value, Inputs, Level 3 | Minimum | Discount rate | Notes Receivable | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	10.50%	8.42%
Fair Value, Inputs, Level 3 | Minimum | Discount rate | Loans (at fair value) | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	9.87%	6.36%
Fair Value, Inputs, Level 3 | Minimum | Credit risk rate | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trailing fees liability, measurement input	0.01%
Fair Value, Inputs, Level 3 | Minimum | Credit risk rate | Notes Receivable | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.59%	0.59%
Fair Value, Inputs, Level 3 | Minimum | Credit risk rate | Loans (at fair value) | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.01%	0.01%
Fair Value, Inputs, Level 3 | Maximum | Discount rate | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trailing fees liability, measurement input	22.82%
Fair Value, Inputs, Level 3 | Maximum | Discount rate | Notes Receivable | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	22.82%	22.27%
Fair Value, Inputs, Level 3 | Maximum | Discount rate | Loans (at fair value) | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	22.82%	22.28%
Fair Value, Inputs, Level 3 | Maximum | Credit risk rate | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trailing fees liability, measurement input	92.98%
Fair Value, Inputs, Level 3 | Maximum | Credit risk rate | Notes Receivable | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	50.69%	50.69%
Fair Value, Inputs, Level 3 | Maximum | Credit risk rate | Loans (at fair value) | Valuation Technique, Discounted Cash Flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	92.98%	93.09%