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Fair Value Measurement - Measurement Inputs (Details) - Valuation Technique, Discounted Cash Flow - Fair Value, Inputs, Level 3	Mar. 31, 2021	Dec. 31, 2020
Minimum | Discount rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.0352	0.0680
Minimum | Discount rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.0301	0.0301
Minimum | Credit risk rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.0021	0.0036
Minimum | Credit risk rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.0004	0.0004
Minimum | Prepayment rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.1269	0.1164
Minimum | Prepayment rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.1560	0.1560
Maximum | Discount rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.1660	0.1699
Maximum | Discount rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.1400	0.1400
Maximum | Credit risk rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.5231	0.5231
Maximum | Credit risk rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.5069	0.5069
Maximum | Prepayment rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.7853	0.7836
Maximum | Prepayment rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.3688	0.3688
Weighted Average | Discount rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.0674	0.0744
Weighted Average | Discount rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.0583	0.0584
Weighted Average | Credit risk rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.2309	0.1982
Weighted Average | Credit risk rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.1740	0.1712
Weighted Average | Prepayment rate | Loans (at fair value)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.3368	0.3103
Weighted Average | Prepayment rate | Notes Receivable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loan receivable, measurement input	0.2767	0.2763

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- Definition

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- Definition

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