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Fair Value of Financial Instruments (Fair Value Methodology) (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential whole loans, at fair value | $ 1,381,113 | $ 1,383,502
Loan purchases excluded from Level 3 fair value methodology disclosures | 470 | 282,500
Discounted cash flow |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential whole loans, at fair value | 829,842 | 700,250
Liquidation model |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential whole loans, at fair value | 551,271 | 683,252
Residential loans, simple average, amount | $ 365 | $ 400
Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Annual change in home prices | 8.00% | 12.20%
Liquidation timeline (in years) | 4 years 6 months | 4 years 6 months
Current value of underlying properties | $ 4,500 | $ 7,950
Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Annual change in home prices | 2.40% | (0.50%)
Liquidation timeline (in years) | 1 month 6 days | 1 month 6 days
Current value of underlying properties | $ 10 | $ 2
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.080 | 0.080
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.038 | 0.045
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.042 | 0.052
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.500 | 0.500
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.062 | 0.061
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.080 | 0.080
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.180 | 0.159
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.007 | 0.009
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.045 | 0.048
Prepayment rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Annual change in home prices | 3.70% | 3.50%
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.230 | 0.241
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.000 | 0.000
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.040 | 0.041
Default rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Liquidation timeline (in years) | 1 year 9 months 18 days | 1 year 9 months 18 days
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 1.000 | 1.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.000 | 0.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.129 | 0.129
Loss severity | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Current value of underlying properties | $ 684 | $ 802

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