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Investments - Mortgage Loans Held for Sale (Details) $ in Thousands | Sep. 30, 2023 USD ($) state investment | Dec. 31, 2022 USD ($)
--- | --- | ---
Gain (Loss) on Securities [Line Items] |  |
Mortgage loans held for sale—at fair value | $ | $ 138,289 | $ 3,549
Mortgage loans held for sale |  |
Gain (Loss) on Securities [Line Items] |  |
Number of investments | investment | 331 |
Unpaid principal balance | $ | $ 139,000 |
Number of states | state | 35 |
Mortgage loans held for sale | Financial Asset, Equal to or Greater than 90 Days Past Due |  |
Gain (Loss) on Securities [Line Items] |  |
Number of investments | investment | 0 |

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