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Securities (Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses) (Details) - USD ($) $ in Thousands | Sep. 30, 2022 | Dec. 31, 2021
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Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 2,290,709 | $ 3,195,732
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 293,439 | 43,236
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 2,366,825 | 383,754
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 453,896 | 14,645
Debt Securities, Available-for-sale, Unrealized Loss Position | 4,657,534 | 3,579,486
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | 747,335 | 57,881
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 1,071,973 | 2,292,062
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 106,441 | 30,777
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 1,757,493 | 176,946
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 346,237 | 7,315
Debt Securities, Available-for-sale, Unrealized Loss Position | 2,829,466 | 2,469,008
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | 452,678 | 38,092
Asset-backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 129,541 | 195,708
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 14,741 | 4,823
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 204,467 | 117,751
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 35,900 | 4,968
Debt Securities, Available-for-sale, Unrealized Loss Position | 334,008 | 313,459
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | 50,641 | 9,791
State and Municipal Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 601,998 | 237,354
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 99,002 | 3,862
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 205,918 | 40,343
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 51,994 | 1,076
Debt Securities, Available-for-sale, Unrealized Loss Position | 807,916 | 277,697
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | 150,996 | 4,938
U.S. Government and Government-Sponsored Enterprise Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 83,992 | 100,813
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 1,478 | 1,988
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 138,881 | 48,714
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 13,420 | 1,286
Debt Securities, Available-for-sale, Unrealized Loss Position | 222,873 | 149,527
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | 14,898 | 3,274
US Treasury Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 111,904 | 157,536
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 10,996 | 831
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 54,402 | 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 5,563 | 0
Debt Securities, Available-for-sale, Unrealized Loss Position | 166,306 | 157,536
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | 16,559 | 831
Non-agency collateralized mortgage obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | 291,301 | 212,259
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss | 60,781 | 955
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 5,664 | 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss | 782 | 0
Debt Securities, Available-for-sale, Unrealized Loss Position | 296,965 | 212,259
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 61,563 | $ 955

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