Income Taxes - Reconciliation of income tax expense computed at statutory rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
Income tax expense at federal statutory rate	$ 360	$ 620
Increase (decrease) resulting from:
Tax-exempt income	(200)	(341)
Bank owned life insurance	(101)	(68)
State income taxes, net of Federal income tax benefit	74	93
Federal rate change		592
Other	(3)	17
Income tax expense (benefit)	$ 130	$ 913