Income Tax, Components of Deferred Tax Asset and Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets, Gross [Abstract]
Deferred Tax Asset, Allowance For Loan Loss	$ 1,411	$ 1,102
Deferred Tax Asset, Bonus	183	296
Deferred Tax Asset Right Of Use Liability	204	198
Deferred Tax Assets, Other	91	88
Deferred Tax Assets, Gross	1,889	1,684
Deferred Tax Liabilities [Abstract]
Deferred Tax Liabilities, Property, Plant and Equipment	199	315
Deferred Tax Liabilities, Unrealized Gains on Available-for-Sale Securities, Gross	2,548	690
Deferred Tax Liabilities, Originated Mortgage Servicing Rights	334	326
Deferred Tax Liabilities, Right Of Use Asset	198	197
Deferred Tax Liabilities, Other	147	165
Deferred Income Tax Liabilities, Gross, Total	3,426	1,693
Deferred Tax Assets (Liabilities), Net	$ (1,537)	$ (9)	$ 1,790