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Securities - Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
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Schedule Of Available For Sale Securities [Line Items] |  |
Available for Sale, Estimated Fair Value, Less than 12 Months | $ 74,900 | $ 55,991
Available for Sale, Unrealized Losses, Less than 12 Months | (457) | (420)
Available for Sale, Estimated Fair Value, 12 Months or More | 237,427 | 215,455
Available for Sale, Unrealized Losses, 12 Months or More | (3,343) | (3,793)
Available for Sale, Estimated Fair Value, Total | 312,327 | 271,446
Available for Sale, Unrealized Losses, Total | (3,800) | (4,213)
Held to Maturity, Estimated Fair Value, Less than 12 Months | 5,344 | 388,714
Held to Maturity, Unrealized Losses, Less than 12 Months | (50) | (5,467)
Held to Maturity, Estimated Fair Value, 12 Months or More | 8,307,773 | 8,882,499
Held to Maturity, Unrealized Losses, 12 Months or More | (928,079) | (1,370,118)
Held to Maturity, Estimated Fair Value, Total | 8,313,117 | 9,271,213
Held to Maturity, Unrealized Losses, Total | (928,129) | (1,375,585)
Corporate Debt Securities [Member] |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available for Sale, Estimated Fair Value, Less than 12 Months |  | 2,040
Available for Sale, Unrealized Losses, Less than 12 Months |  | (60)
Available for Sale, Estimated Fair Value, Total |  | 2,040
Available for Sale, Unrealized Losses, Total |  | (60)
Held to Maturity, Estimated Fair Value, 12 Months or More | 9,840 | 8,160
Held to Maturity, Unrealized Losses, 12 Months or More | (2,160) | (3,840)
Held to Maturity, Estimated Fair Value, Total | 9,840 | 8,160
Held to Maturity, Unrealized Losses, Total | (2,160) | (3,840)
Collateralized Mortgage Obligations [Member] |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available for Sale, Estimated Fair Value, Less than 12 Months | 65,479 | 47,114
Available for Sale, Unrealized Losses, Less than 12 Months | (395) | (307)
Available for Sale, Estimated Fair Value, 12 Months or More | 147,510 | 125,942
Available for Sale, Unrealized Losses, 12 Months or More | (2,604) | (2,926)
Available for Sale, Estimated Fair Value, Total | 212,989 | 173,056
Available for Sale, Unrealized Losses, Total | (2,999) | (3,233)
Held to Maturity, Estimated Fair Value, Less than 12 Months | 566 | 28,362
Held to Maturity, Unrealized Losses, Less than 12 Months | (5) | (663)
Held to Maturity, Estimated Fair Value, 12 Months or More | 171,256 | 179,855
Held to Maturity, Unrealized Losses, 12 Months or More | (12,478) | (23,465)
Held to Maturity, Estimated Fair Value, Total | 171,822 | 208,217
Held to Maturity, Unrealized Losses, Total | (12,483) | (24,128)
Mortgage-backed Securities [Member] |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Available for Sale, Estimated Fair Value, Less than 12 Months | 9,421 | 6,837
Available for Sale, Unrealized Losses, Less than 12 Months | (62) | (53)
Available for Sale, Estimated Fair Value, 12 Months or More | 89,917 | 89,513
Available for Sale, Unrealized Losses, 12 Months or More | (739) | (867)
Available for Sale, Estimated Fair Value, Total | 99,338 | 96,350
Available for Sale, Unrealized Losses, Total | (801) | (920)
Held to Maturity, Estimated Fair Value, Less than 12 Months | 4,778 | 331,265
Held to Maturity, Unrealized Losses, Less than 12 Months | (45) | (4,647)
Held to Maturity, Estimated Fair Value, 12 Months or More | 8,101,183 | 8,646,541
Held to Maturity, Unrealized Losses, 12 Months or More | (912,010) | (1,340,416)
Held to Maturity, Estimated Fair Value, Total | 8,105,961 | 8,977,806
Held to Maturity, Unrealized Losses, Total | (912,055) | (1,345,063)
U.S. Government Agencies [Member] |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Held to Maturity, Estimated Fair Value, Less than 12 Months |  | 5,817
Held to Maturity, Unrealized Losses, Less than 12 Months |  | (44)
Held to Maturity, Estimated Fair Value, 12 Months or More | 1,972 |
Held to Maturity, Unrealized Losses, 12 Months or More | (1) |
Held to Maturity, Estimated Fair Value, Total | 1,972 | 5,817
Held to Maturity, Unrealized Losses, Total | (1) | (44)
States and Political Subdivisions [Member] |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Held to Maturity, Estimated Fair Value, Less than 12 Months |  | 23,270
Held to Maturity, Unrealized Losses, Less than 12 Months |  | (113)
Held to Maturity, Estimated Fair Value, 12 Months or More | 23,522 | 47,943
Held to Maturity, Unrealized Losses, 12 Months or More | (1,430) | (2,397)
Held to Maturity, Estimated Fair Value, Total | 23,522 | 71,213
Held to Maturity, Unrealized Losses, Total | $ (1,430) | $ (2,510)

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