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Investments (Narrative) (Details) - USD ($) | Feb. 01, 2022 | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | --- | ---
Investments [Abstract] |  |  |
Transfer to Held-to-maturity | $ 139,000,000.0 |  |
Net unrealized (losses)/gains on all other AFS securities | (8,400,000) |  |
Gain (loss) on transfer to Held-to-maturity | $ 0 |  |
Available-for-sale securities pledged as collateral |  | $ 58,700,000 |
Held-to-maturity securities, allowance for credit losses |  | $ 45,000 | $ 0

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