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Available-for-Sale and Held-to-Maturity Securities (Schedule of Contractual Maturities) (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
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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 |  | $ 85,380 | [1] | $ 15,877
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 223,749 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value |  | 386,538 | [1] | 380,362
Availably-for-sale Securities, debt maturities, after ten years, Fair Value |  | 816,566 | [1] | 952,319
Available-for-sale Securities, debt maturities, Fair Value |  | 1,512,233 | [1] | 1,636,041
Held-to-maturity Securities, debt maturities, after five year through ten, Amortized Cost |  | 2,765,980 |  | 2,413,239
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost |  | 3,134,399 |  | 3,577,212
Held-to-maturity Securities, Amortized cost | [2] | 5,900,379 |  | 5,990,451
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 | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 2,135 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 0 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 2,135 | [1] | 2,148
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 | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 2,294 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 0 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 2,294 | [1] | 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 | [1] | 85,380 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 219,025 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 233,445 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 537,850 | [1] | 566,294
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 | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 295 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 92,085 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 622,870 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 715,250 | [1] | 791,022
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 | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 0 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 65,695 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 65,695 | [1] | 66,113
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 | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 332 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 332 | [1] | 388
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 | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after one year through five, Fair Value | [1] | 0 |  |
Available-for-sale Securities, debt maturities, after five through ten years, fair value | [1] | 60,676 |  |
Availably-for-sale Securities, debt maturities, after ten years, Fair Value | [1] | 128,001 |  |
Available-for-sale Securities, debt maturities, Fair Value |  | 188,677 | [1] | $ 207,725
Held-to-maturity Securities, debt maturities, after five year through ten, Amortized Cost |  | 2,765,980 |  |
Held-to-maturity Securities, debt maturities, after ten years, Amortized Cost |  | 3,134,399 |  |
Held-to-maturity Securities, Amortized cost |  | $ 5,900,379 |  |
[1] | Due to the immaterial amount of income recognized on tax-exempt securities, yields were not calculated on a tax-equivalent basis.
[2] | 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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