Securitization Transactions (Schedule of Assets and Liabilities Attributable to Consolidated VIEs) (Details) - USD ($) $ in Thousands |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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|---|---|---|---|---|---|---|---|---|---|
| Variable Interest Entity [Line Items] | |||||||||
| Fair Value | $ 2,939,311 | ||||||||
| Interest and Dividends Payable | 7,159 | ||||||||
| Other secured borrowings, at fair value | $ 754,921 | [1] | $ 594,396 | [1] | 297,948 | ||||
| Loans, at fair value | [1],[2] | 1,453,480 | 1,412,426 | ||||||
| Real estate owned | [1],[2] | 23,598 | 30,584 | ||||||
| Investment related receivables | [1] | 49,317 | 123,120 | ||||||
| Residential mortgage loans | |||||||||
| Variable Interest Entity [Line Items] | |||||||||
| Loans, at fair value | 1,187,069 | 932,203 | |||||||
| Consolidated Entities [Member] | |||||||||
| Variable Interest Entity [Line Items] | |||||||||
| Fair Value | 314,202 | ||||||||
| Interest and Dividends Receivable | 3,527 | ||||||||
| Interest and Dividends Payable | 103 | ||||||||
| Other secured borrowings, at fair value | $ 297,948 | ||||||||
| Consolidated Entities [Member] | Non-QM loan securitization | |||||||||
| Variable Interest Entity [Line Items] | |||||||||
| Other secured borrowings, at fair value | 754,921 | 594,396 | |||||||
| Investment related receivables | 15,544 | 10,409 | |||||||
| Consolidated Entities [Member] | Residential mortgage loans | Securitized loans [Member] | Non-QM loan securitization | |||||||||
| Variable Interest Entity [Line Items] | |||||||||
| Loans, at fair value | 801,343 | 628,415 | |||||||
| Real estate owned | $ 0 | $ 658 | |||||||
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