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Federal Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Federal statutory tax rate	21.00%	34.00%	21.00%	34.00%
Income taxes at 34% statutory rate	$ 851	$ 1,458	$ 2,389	$ 4,317
Interest income on tax exempt municipal securities	(259)	(452)	(797)	(1,361)
Earnings on corporate owned life insurance policies	(35)	(60)	(109)	(183)
Effect of tax credits	(200)	(186)	(601)	(566)
Other	(6)	(18)	(25)	(54)
Total effect of nontaxable income	(500)	(716)	(1,532)	(2,164)
Effect of nondeductible expenses	8	8	30	27
Federal income tax expense	$ 359	$ 750	$ 887	$ 2,180

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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