Federal Income Taxes (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation between (tax -benefit) expense
Statutory tax expense	$ 2,301	$ 2,039	$ 1,903
Tax effect of non-taxable interest income	(663)	(628)	(600)
Tax effect of earnings on bank-owned life insurance-net	(414)	(112)	(115)
Tax effect of deferred tax valuation reversal		(94)
Change in corporate tax rate	1,246
Tax effect of low income housing credit	(149)	(142)	(54)
Tax effect of non-deductible expenses	96	64	85
Federal income tax expense (benefit)	$ 2,417	$ 1,127	$ 1,219