Loans, Past Due And Accruing Restructured (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing receivables, non accruals, past due, and accruing restructured loans [Line Items]
Total non-accrual loans	$ 2,744	$ 2,965
Past-due 90 days or more and still accruing	146	0
Total non-accrual and past-due 90 days or more and still accruing	2,890	2,965
Accruing restructured loans	10,366	10,469
Total	13,256	13,434
Commercial and industrial [Member]
Financing receivables, non accruals, past due, and accruing restructured loans [Line Items]
Total non-accrual loans	0	0
Commercial Secured By Real Estate [Member]
Financing receivables, non accruals, past due, and accruing restructured loans [Line Items]
Total non-accrual loans	1,876	2,183
Agricultural [Member]
Financing receivables, non accruals, past due, and accruing restructured loans [Line Items]
Total non-accrual loans	177	178
Residential Real Estate [Member]
Financing receivables, non accruals, past due, and accruing restructured loans [Line Items]
Total non-accrual loans	691	604
Consumer [Member]
Financing receivables, non accruals, past due, and accruing restructured loans [Line Items]
Total non-accrual loans	$ 0	$ 0