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Securities - Amortized Cost and Estimated Fair Value of Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Jun. 30, 2025 | Dec. 31, 2024 | Sep. 30, 2024 | Jun. 30, 2024 | Dec. 31, 2023
--- | --- | --- | --- | --- | --- | ---
Available for sale: |  |  |  |  |  |
Amortized Cost | $ 1,182,686 |  | $ 1,237,433 |  |  |
Gross Unrealized Gains | 6,584 |  | 686 |  |  |
Gross Unrealized Losses | (84,481) |  | (135,591) |  |  |
Fair Value | 1,104,789 |  | 1,102,528 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 1,104,789 |  | 1,102,528 |  |  |
Held to maturity: |  |  |  |  |  |
Amortized Cost | 10,602 |  |  |  |  |
Fair Value | 10,018 |  | 10,456 |  |  |
Allowance for Credit Losses | (43) | $ (47) | (50) | $ (52) | $ (57) | $ (63)
Net Carrying Amount | 10,559 |  | 11,095 |  |  |
Securities carried at fair value through income: |  |  |  |  |  |
Fair Value | 6,203 |  | 6,512 |  |  |
State and municipal securities |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 324,806 |  | 299,642 |  |  |
Gross Unrealized Gains | 799 |  | 216 |  |  |
Gross Unrealized Losses | (33,021) |  | (43,882) |  |  |
Fair Value | 292,584 |  | 255,976 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 292,584 |  | 255,976 |  |  |
Held to maturity: |  |  |  |  |  |
Amortized Cost | 10,602 |  | 11,145 |  |  |
Gross Unrealized Gains | 0 |  | 0 |  |  |
Gross Unrealized Losses | (584) |  | (689) |  |  |
Fair Value | 10,018 |  | 10,456 |  |  |
Allowance for Credit Losses | (43) |  | (50) |  |  |
Net Carrying Amount | 10,559 |  | 11,095 |  |  |
Securities carried at fair value through income: |  |  |  |  |  |
Amortized Cost | 6,200 |  | 6,515 |  |  |
Fair Value | 6,203 |  | 6,512 |  |  |
Net Carrying Amount | 6,203 |  | 6,512 |  |  |
Corporate bonds |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 64,104 |  | 83,041 |  |  |
Gross Unrealized Gains | 148 |  | 445 |  |  |
Gross Unrealized Losses | (2,417) |  | (5,250) |  |  |
Fair Value | 61,835 |  | 78,236 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 61,835 |  | 78,236 |  |  |
U.S. treasury and government agency securities |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 3,847 |  | 14,742 |  |  |
Gross Unrealized Gains | 1 |  | 2 |  |  |
Gross Unrealized Losses | (720) |  | (939) |  |  |
Fair Value | 3,128 |  | 13,805 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 3,128 |  | 13,805 |  |  |
Commercial mortgage-backed securities |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 17,047 |  | 49,943 |  |  |
Gross Unrealized Gains | 20 |  | 0 |  |  |
Gross Unrealized Losses | (1,819) |  | (5,659) |  |  |
Fair Value | 15,248 |  | 44,284 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 15,248 |  | 44,284 |  |  |
Residential mortgage-backed securities |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 476,073 |  | 598,380 |  |  |
Gross Unrealized Gains | 4,131 |  | 8 |  |  |
Gross Unrealized Losses | (31,136) |  | (57,554) |  |  |
Fair Value | 449,068 |  | 540,834 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 449,068 |  | 540,834 |  |  |
Commercial collateralized mortgage obligations |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 83,272 |  | 31,263 |  |  |
Gross Unrealized Gains | 435 |  | 0 |  |  |
Gross Unrealized Losses | (1,121) |  | (2,697) |  |  |
Fair Value | 82,586 |  | 28,566 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | 82,586 |  | 28,566 |  |  |
Residential collateralized mortgage obligations |  |  |  |  |  |
Available for sale: |  |  |  |  |  |
Amortized Cost | 213,537 |  | 160,422 |  |  |
Gross Unrealized Gains | 1,050 |  | 15 |  |  |
Gross Unrealized Losses | (14,247) |  | (19,610) |  |  |
Fair Value | 200,340 |  | 140,827 |  |  |
Allowance for Credit Losses | 0 |  | 0 |  |  |
Net Carrying Amount | $ 200,340 |  | $ 140,827 |  |  |

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