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Derivatives - Schedule of Interest Rate Hedging Instruments (Details) - USD ($) | Sep. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Derivative [Line Items] |  |
Derivative assets | $ 4,138,000 | $ 54,361,000
Derivative liabilities | 3,662,000 | 0
U.S. Treasury futures |  |
Derivative [Line Items] |  |
Derivative assets | 5,600,000 |
Derivative Instruments Not Designated as Hedging Instruments, at Carrying Value | 0 |
Derivative liabilities |  | 219,900,000
U.S. Treasury futures | Short position | Not Designated as Hedging Instrument, Economic Hedge |  |
Derivative [Line Items] |  |
Notional balance | (4,355,000,000) | (4,880,000,000)
Interest rate swaps |  |
Derivative [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, at Carrying Value | 0 |
Derivative liabilities | 10,200,000 | 0
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge |  |
Derivative [Line Items] |  |
Notional balance | $ (1,535,000,000) | $ 0
Derivative, Average Fixed Interest Rate | 3.46% |
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | Less than 5 years |  |
Derivative [Line Items] |  |
Notional balance | $ (1,275,000,000) |
Derivative, Average Fixed Interest Rate | 3.42% |
Interest rate swaps | Short position | Not Designated as Hedging Instrument, Economic Hedge | Less than 7 years |  |
Derivative [Line Items] |  |
Notional balance | $ (260,000,000) |
Derivative, Average Fixed Interest Rate | 3.63% |

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