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Available-for-Sale and Held-to-Maturity Securities (Contractual Maturities) (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Dec. 31, 2024
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Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | $ 103,267 | $ 78,080
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 110,966 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 297,508 | 352,736
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 1,176,895 | 1,016,733
Available-for-sale Securities, debt maturities, Fair Value |  | 1,688,636 | 1,584,598
Held-to-maturity Securities, debt maturities, after five year through ten, Amortized Cost |  | 1,714,752 | 3,063,278
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost |  | 4,568,264 | 3,370,492
Held-to-maturity securities, at amortized cost | [1] | 6,458,002 | 6,524,954
U.S. Government Agency Securities [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 2,361 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 0 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, Fair Value |  | 2,361 |
State and Municipal Securities [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 2,351 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 0 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, Fair Value |  | 2,351 |
Corporate Fixed Income Securities [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 103,267 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 101,291 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 197,759 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 5,035 |
Available-for-sale Securities, debt maturities, Fair Value |  | 407,352 |
Mortgage-Backed Securities [Member] | Agency Securities [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 4,963 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 74,563 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 1,073,434 |
Available-for-sale Securities, debt maturities, Fair Value |  | 1,152,960 | 921,563
Mortgage-Backed Securities [Member] | Commercial [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 0 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 10,976 |
Available-for-sale Securities, debt maturities, Fair Value |  | 10,976 | 67,956
Mortgage-Backed Securities [Member] | Non-Agency [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 158 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, Fair Value |  | 158 | 199
Asset-Backed Securities [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Available-for-sale Securities, debt maturities, within one year, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value |  | 0 |
Available-for-sale Securities, debt maturities, after five year through ten years, fair value |  | 25,028 |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 87,450 |
Available-for-sale Securities, debt maturities, Fair Value |  | 112,478 | $ 126,273
Held-to-maturity Securities, debt maturities, within one year, Amortized Cost |  | 0 |
Held-to-maturity Securities, debt maturities, after one year through five, Amortized Cost |  | 174,986 |
Held-to-maturity Securities, debt maturities, after five year through ten, Amortized Cost |  | 1,714,752 |
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost |  | 4,568,264 |
Held-to-maturity securities, at amortized cost |  | $ 6,458,002 |
[1] | Held-to-maturity securities are carried in the consolidated statements of financial condition at amortized cost, and the changes in the value of these securities, other than impairment charges, are not reported on the consolidated financial statements.

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