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AFS Securities (Amortized cost and fair value of AFS securities by contractual maturity) (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021
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Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | $ 15,866 |
Maturing, After One Year But Within Five Years | 284,859 |
Maturing, After Five Years But Within Ten Years | 26,622 |
Maturing, After Ten Years | 26,840 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 208,769 |
Amortized Cost | 562,956 | $ 485,710
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less, Fair value | 15,917 |
Maturing, After One Year But Within Five Years, Fair value | 271,929 |
Maturing, After Five Years But Within Ten Years, Fair value | 26,157 |
Maturing, After Ten Years, Fair value | 26,030 |
Securities With Variable Monthly Payments or Noncontractual Maturities, Fair value | 204,886 |
Total, Fair value | 544,919 | 490,601
States and political subdivisions [Member] |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 15,866 |
Maturing, After One Year But Within Five Years | 52,934 |
Maturing, After Five Years But Within Ten Years | 18,472 |
Maturing, After Ten Years | 26,840 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 0 |
Amortized Cost | 114,112 | 116,836
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Total, Fair value | 114,015 | 121,205
Auction rate money market preferred [Member] |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 0 |
Maturing, After One Year But Within Five Years | 0 |
Maturing, After Five Years But Within Ten Years | 0 |
Maturing, After Ten Years | 0 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 3,200 |
Amortized Cost | 3,200 | 3,200
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Total, Fair value | 2,867 | 3,242
Mortgage-backed securities [Member] |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 0 |
Maturing, After One Year But Within Five Years | 0 |
Maturing, After Five Years But Within Ten Years | 0 |
Maturing, After Ten Years | 0 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 50,775 |
Amortized Cost | 50,775 | 54,710
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Total, Fair value | 49,578 | 56,148
Collateralized mortgage obligations [Member] |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 0 |
Maturing, After One Year But Within Five Years | 0 |
Maturing, After Five Years But Within Ten Years | 0 |
Maturing, After Ten Years | 0 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 154,794 |
Amortized Cost | 154,794 | 90,435
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Total, Fair value | 152,441 | 92,301
Corporate Debt Securities |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 0 |
Maturing, After One Year But Within Five Years | 0 |
Maturing, After Five Years But Within Ten Years | 8,150 |
Maturing, After Ten Years | 0 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 0 |
Amortized Cost | 8,150 | 8,150
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Total, Fair value | 7,750 | 8,002
US Treasury Securities |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 0 |
Maturing, After One Year But Within Five Years | 231,925 |
Maturing, After Five Years But Within Ten Years | 0 |
Maturing, After Ten Years | 0 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 0 |
Amortized Cost | 231,925 | 212,379
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Total, Fair value | $ 218,268 | $ 209,703

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