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Industry Segment Information (Narrative) (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Segment Reporting [Abstract] |  |  |
Statutory federal tax rate | 21.00% | 21.00% | 35.00%
Tax-equivalent adjustment | $ 2,084,000 | $ 2,422,000 | $ 5,691,000

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