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Income Taxes (Income Tax Expense Differed From Statutory Federal Income Tax Rate) (Details) | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Income Tax Disclosure [Abstract] |  |  |
Statutory federal tax rate | 21.00% | 21.00% | 35.00%
Tax exempt interest income | (1.90%) | (2.60%) | (5.60%)
Tax credits and adjustments | (3.00%) | (0.30%) | (6.70%)
Non-taxable earnings on company owned life insurance | (0.60%) | (0.80%) | (1.40%)
State taxes, net of federal tax benefit | 1.90% | 1.50% | 1.10%
Nondeductible expenses | 0.20% | 0.20% | 0.30%
Goodwill and contingent consideration adjustments |  | 1.00% | 0.30%
Other, net | 0.20% | 0.20% | (0.10%)
Effective tax rate | 17.80% | 20.20% | 22.90%

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