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AFS Securities (Amortized cost and fair value of AFS securities by contractual maturity) (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
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Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | $ 28,932 |
Maturing, After One Year But Within Five Years | 70,795 |
Maturing, After Five Years But Within Ten Years | 38,342 |
Maturing, After Ten Years | 26,936 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 258,975 |
Amortized Cost | 423,980 | $ 501,245
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less, Fair value | 29,091 |
Maturing, After One Year But Within Five Years, Fair value | 72,332 |
Maturing, After Five Years But Within Ten Years, Fair value | 39,875 |
Maturing, After Ten Years, Fair value | 28,454 |
Securities With Variable Monthly Payments or Noncontractual Maturities, Fair value | 260,087 |
Total, Fair value | 429,839 | $ 494,834
States and political subdivisions [Member] |  |
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract] |  |
Maturing, Due in One Year or Less | 28,932 |
Maturing, After One Year But Within Five Years | 70,795 |
Maturing, After Five Years But Within Ten Years | 38,342 |
Maturing, After Ten Years | 26,936 |
Securities With Variable Monthly Payments or Noncontractual Maturities | 0 |
Amortized Cost | 165,005 |
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 |
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 | 139,831 |
Amortized Cost | 139,831 |
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 | 115,944 |
Amortized Cost | $ 115,944 |

X
- Definition Available-for-sale Securities, Debt Maturities, With Variable Monthly Payments Or Without Single Maturity Date, Amortized Cost Basis + References No definition available. + Details
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- Definition Available-for-sale Securities, With Variable Monthly Payments Or Without Single Maturity Date, Fair Value + References No definition available. + Details
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
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- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Amortized cost of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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- Definition Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. + References No definition available. + Details
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