Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Unpaid Principal Balance
With no related allowance recorded	$ 1,322		$ 1,353
With an allowance recorded	67		68
Total	1,389		1,421
Recorded Investment
With no related allowance recorded	1,322		1,353
With an allowance recorded	67		68
Total	1,389		1,421
Allowance for Loan Losses Allocated
Total	50		48
Average Recorded Investment
Total	1,400	$ 2,242
Interest Income Recognized
Total	19	27
Cash Basis Interest Recognized
Total	1	2
Commercial
Average Recorded Investment
Total		1
Residential Real Estate
Average Recorded Investment
Total	137	157
Interest Income Recognized
Total	2	2
Cash Basis Interest Recognized
Total		1
Real estate | Residential Real Estate
Unpaid Principal Balance
With no related allowance recorded	137		147
Recorded Investment
With no related allowance recorded	137		147
Other | Commercial Real Estate
Unpaid Principal Balance
With no related allowance recorded	1,182		1,202
With an allowance recorded	67		68
Recorded Investment
With no related allowance recorded	1,182		1,202
With an allowance recorded	67		68
Allowance for Loan Losses Allocated
Total	50		48
Average Recorded Investment
Total	1,260	2,078
Interest Income Recognized
Total	17	25
Cash Basis Interest Recognized
Total	1	1
Other | Consumer
Unpaid Principal Balance
With no related allowance recorded	3		4
Recorded Investment
With no related allowance recorded	3		$ 4
Average Recorded Investment
Total	$ 3	$ 6