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Other Assets (Capital Contributions Made to Loan Origination Partners) (Details) - USD ($) |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jul. 01, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Mar. 31, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Other Assets [Line Items] |  |  |  |  |  |
Gain on investment in Lima One common equity (Note 16) |  | $ 38,933,000 | $ 0 |  | $ 38,933,000 | $ 0
Impairment (reversal) on investment |  | (10,000,000) |  |  |  |
Lima One |  |  |  |  |  |
Other Assets [Line Items] |  |  |  |  |  |
Gain on investment in Lima One common equity (Note 16) | $ 38,900,000 |  |  |  |  |
Impairment (reversal) on investment | $ (5,000,000) |  |  | $ 21,000,000 |  |
Loan Originators |  |  |  |  |  |
Other Assets [Line Items] |  |  |  |  |  |
Equity method investments |  | 23,200,000 |  |  | 23,200,000 |
Impairment (reversal) on investment |  | 0 |  |  | 0 | $ 65,200,000
Company’s residential whole loans at carrying value are serviced by entities the Company has an investment in |  | 1,000,000,000 |  |  | 1,000,000,000 |
Preferred Stock | Loan Originators |  |  |  |  |  |
Other Assets [Line Items] |  |  |  |  |  |
Equity method investments |  | $ 67,800,000 |  |  | $ 67,800,000 |

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