Investment in Loans (Schedule of Consumer Loans) (Details) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|
Sep. 30, 2021 |
Dec. 31, 2020 |
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| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||||
| Unpaid Principal Balance | $ 1,940,279 | $ 1,417,054 | ||||
| Unamortized Premium (Discount) | (143,084) | (196,118) | ||||
| Loans, at fair value | [1],[2] | $ 1,996,529 | $ 1,453,480 | |||
| Weighted Average | ||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||||
| Weighted average life | 5 years 11 months 4 days | 4 years 5 months 26 days | ||||
| Consumer loans | ||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||||
| Fair value of charged-off loans | $ 300 | $ 600 | ||||
| Unpaid Principal Balance | 53,515 | 48,180 | ||||
| Unamortized Premium (Discount) | 2,405 | 72 | ||||
| Investments, at fair value, Cost | 55,920 | 48,252 | ||||
| Gains | 910 | 1,160 | ||||
| Losses | (1,154) | (1,887) | ||||
| Loans, at fair value | $ 55,676 | $ 47,525 | ||||
| Consumer loans | Weighted Average | ||||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||||
| Weighted average life | 11 months 15 days | 1 year 14 days | ||||
| Delinquency (Days) | 3 days | 7 days | ||||
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