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Securities - Amortized Cost and Fair Value of Securities Available for Sale (Details) - USD ($) | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Investments, Debt and Equity Securities [Abstract] |  |
Allowance for credit loss | $ 0 | $ 0
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 2,599,397,000 | 968,927,000
Gross Unrealized Gains | 15,736,000 | 694,000
Gross Unrealized Losses | (102,483,000) | (138,608,000)
Fair Value | 2,512,650,000 | 831,013,000
Obligations of states and political subdivisions |  |
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 270,696,000 | 20,266,000
Gross Unrealized Gains | 5,318,000 | 57,000
Gross Unrealized Losses | (2,365,000) | (2,269,000)
Fair Value | 273,649,000 | 18,054,000
Other debt securities |  |
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 364,473,000 | 130,175,000
Gross Unrealized Gains | 871,000 | 440,000
Gross Unrealized Losses | (3,239,000) | (2,655,000)
Fair Value | 362,105,000 | 127,960,000
Mortgage backed securities issued by U.S. Government agencies or sponsored enterprises | Residential mortgage backed securities: |  |
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 710,105,000 | 185,292,000
Gross Unrealized Gains | 3,709,000 | 81,000
Gross Unrealized Losses | (17,508,000) | (24,468,000)
Fair Value | 696,306,000 | 160,905,000
Mortgage backed securities issued by U.S. Government agencies or sponsored enterprises | Commercial mortgage backed securities: |  |
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 100,337,000 | 11,373,000
Gross Unrealized Gains | 221,000 | 0
Gross Unrealized Losses | (799,000) | (751,000)
Fair Value | 99,759,000 | 10,622,000
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises | Residential mortgage backed securities: |  |
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 739,005,000 | 475,311,000
Gross Unrealized Gains | 2,978,000 | 75,000
Gross Unrealized Losses | (59,903,000) | (86,870,000)
Fair Value | 682,080,000 | 388,516,000
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises | Commercial mortgage backed securities: |  |
Amortized cost and fair value of securities available for sale |  |
Amortized Cost | 414,781,000 | 146,510,000
Gross Unrealized Gains | 2,639,000 | 41,000
Gross Unrealized Losses | (18,669,000) | (21,595,000)
Fair Value | $ 398,751,000 | $ 124,956,000

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