Federal Income Taxes (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Composition of income tax expense (benefit)
Current		$ 1,150	$ 407	$ 1,199
Deferred		209	1,008	(28)
Change in corporate tax rate	[1]			1,246
Federal income tax expense (benefit)		$ 1,359	$ 1,415	$ 2,417

[1] The tax act lowers the base corporate tax rate from 35% to 21% which was applied to the existing deferred tax balance.