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Federal Income Taxes (Parenthetical) (Details 3)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Line Items]      
Corporate tax rate 21.00% 34.00% 34.00%
Maximum      
Income Tax Disclosure [Line Items]      
Corporate tax rate   35.00%