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INVESTMENTS (Summary of Amortized Costs and Estimated Fair Values of Available-For-Sale Securities) (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
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Debt Securities, Available-for-sale [Abstract] |  |
Amortized Cost, Total | $ 935,635 | $ 673,003
Available-for-sale securities, at fair value (amortized cost of $935,635 and $673,003, respectively) | 889,765 | 593,749
Obligations of states and political subdivisions |  |
Debt Securities, Available-for-sale [Abstract] |  |
Amortized Cost, Total | 5,418 | 5,423
Unrealized Gains | 1 | 0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | 22 | 134
Available-for-sale securities, at fair value (amortized cost of $935,635 and $673,003, respectively) | 5,397 | 5,289
MBS issued or guaranteed by U.S. government-sponsored enterprises |  |
Debt Securities, Available-for-sale [Abstract] |  |
Amortized Cost, Total | 688,685 | 493,766
Unrealized Gains | 6,838 | 353
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | 46,244 | 69,163
Available-for-sale securities, at fair value (amortized cost of $935,635 and $673,003, respectively) | 649,279 | 424,956
CMO issued or guaranteed by U.S. government-sponsored enterprises |  |
Debt Securities, Available-for-sale [Abstract] |  |
Amortized Cost, Total | 223,820 | 156,131
Unrealized Gains | 1,076 | 502
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | 6,892 | 9,154
Available-for-sale securities, at fair value (amortized cost of $935,635 and $673,003, respectively) | 218,004 | 147,479
Subordinated corporate bonds |  |
Debt Securities, Available-for-sale [Abstract] |  |
Amortized Cost, Total | 17,712 | 17,683
Unrealized Gains | 0 | 0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | 627 | 1,658
Available-for-sale securities, at fair value (amortized cost of $935,635 and $673,003, respectively) | 17,085 | 16,025
Total AFS debt securities |  |
Debt Securities, Available-for-sale [Abstract] |  |
Amortized Cost, Total | 935,635 | 673,003
Unrealized Gains | 7,915 | 855
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | 53,785 | 80,109
Available-for-sale securities, at fair value (amortized cost of $935,635 and $673,003, respectively) | $ 889,765 | $ 593,749

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