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Securities, Available for Sale (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2024 | Mar. 31, 2023 | Dec. 31, 2023
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | $ 1,607,983 |  | $ 1,615,078
Unrealized gains | 63 |  | 47
Unrealized losses | (189,575) |  | (184,267)
Estimated fair value | 1,418,471 |  | 1,430,858
Allowance for credit losses on AFS securities | 0 |  | 0
Gross realized gains | 0 |  |
Gross realized losses | 0 | $ 5,000 |
Gain recognized on sale of previously written-off security | 2,300 |  |
U.S. Treasury [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 133,442 |  | 133,302
Unrealized gains | 0 |  | 0
Unrealized losses | (8,759) |  | (8,278)
Estimated fair value | 124,683 |  | 125,024
Federal Agency [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 248,375 |  | 248,384
Unrealized gains | 0 |  | 0
Unrealized losses | (35,071) |  | (33,644)
Estimated fair value | 213,304 |  | 214,740
State & Municipal [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 96,054 |  | 96,251
Unrealized gains | 1 |  | 11
Unrealized losses | (10,022) |  | (9,956)
Estimated fair value | 86,033 |  | 86,306
Mortgage-Backed, Government Sponsored Enterprises [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 387,479 |  | 399,532
Unrealized gains | 3 |  | 7
Unrealized losses | (45,461) |  | (44,264)
Estimated fair value | 342,021 |  | 355,275
Mortgage-Backed, U.S. Government Agency Securities [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 71,036 |  | 74,281
Unrealized gains | 10 |  | 14
Unrealized losses | (7,520) |  | (7,302)
Estimated fair value | 63,526 |  | 66,993
Collateralized Mortgage Obligations, Government-Sponsored Enterprises [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 452,853 |  | 452,715
Unrealized gains | 49 |  | 15
Unrealized losses | (50,135) |  | (48,257)
Estimated fair value | 402,767 |  | 404,473
Collateralized Mortgage Obligations, U.S. Government Agency Securities [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 170,293 |  | 162,171
Unrealized gains | 0 |  | 0
Unrealized losses | (26,034) |  | (25,100)
Estimated fair value | 144,259 |  | 137,071
Corporate [Member] |  |  |
Debt securities, available-for-sale [Abstract] |  |  |
Amortized cost | 48,451 |  | 48,442
Unrealized gains | 0 |  | 0
Unrealized losses | (6,573) |  | (7,466)
Estimated fair value | $ 41,878 |  | $ 40,976
Loss on the write-off of an AFS debt security |  | $ 5,000 |

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