Income Taxes - Reconciliation of income tax expense computed at statutory rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Income tax expense at federal statutory rate	$ 453	$ 431
(Decrease) increase resulting from:
Tax-exempt income	(75)	(72)
Bank owned life insurance	(33)	(34)
State income taxes, net of Federal income tax benefit	146	127
Income tax expense	$ 491	$ 452