Loans (Schedule of Recorded Investment in Nonaccrual Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	$ 9,479	$ 11,091
Loans Past Due 90 Days or More & Still Accruing	1,121	742
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	3,105	4,753
Loans Past Due 90 Days or More & Still Accruing	0	0
Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	4,502	4,618
Loans Past Due 90 Days or More & Still Accruing	893	474
Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	697	748
Loans Past Due 90 Days or More & Still Accruing	228	268
Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	188	199
Loans Past Due 90 Days or More & Still Accruing	0	0
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	71	286
Loans Past Due 90 Days or More & Still Accruing	0	0
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	916	487
Loans Past Due 90 Days or More & Still Accruing	0	0
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-Accrual Loans	822	866
Loans Past Due 90 Days or More & Still Accruing	$ 0	$ 0