Loans (Schedule of Aging of Recorded Investment in Past Due Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	$ 1,523,370	[1],[2]	$ 1,457,768	[3],[4]
Loans Past Due	6,455	[2]	6,942	[4]
Loans Not Past Due	1,516,915	[2]	1,450,826	[4]
Accrued interest	6,085		5,778
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	405,920	[1]	380,851	[3]
Loans Past Due	556		776
Loans Not Past Due	405,364		380,075
Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	601,996	[1]	584,426	[3]
Loans Past Due	1,249		1,267
Loans Not Past Due	600,747		583,159
Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	239,672	[1]	219,640	[3]
Loans Past Due	0		100
Loans Not Past Due	239,672		219,540
Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	91,178	[1]	86,570	[3]
Loans Past Due	635		469
Loans Not Past Due	90,543		86,101
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	47,602	[1]	48,732	[3]
Loans Past Due	563		235
Loans Not Past Due	47,039		48,497
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	137,002	[1]	137,549	[3]
Loans Past Due	3,452		4,095
Loans Not Past Due	133,550		133,454
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	3,355	[2]	3,532	[4]
30-59 Days Past Due | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	444		628
30-59 Days Past Due | Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	0		504
30-59 Days Past Due | Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	0		25
30-59 Days Past Due | Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	364		197
30-59 Days Past Due | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	409		132
30-59 Days Past Due | Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	2,138		2,046
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	398	[2]	371	[4]
60-89 Days Past Due | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	44		0
60-89 Days Past Due | Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	39		10
60-89 Days Past Due | Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	0		0
60-89 Days Past Due | Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	45		4
60-89 Days Past Due | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	60		28
60-89 Days Past Due | Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	210		329
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	2,702	[2]	3,039	[4]
90 Days or More Past Due | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	68		148
90 Days or More Past Due | Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	1,210		753
90 Days or More Past Due | Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	0		75
90 Days or More Past Due | Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	226		268
90 Days or More Past Due | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	94		75
90 Days or More Past Due | Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	1,104		1,720
Receivables Acquired with Deteriorated Credit Quality | Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	6,924		8,361
Loans Past Due	36		648
Loans Not Past Due	6,888		7,713
Receivables Acquired with Deteriorated Credit Quality | 30-59 Days Past Due | Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	36		0
Receivables Acquired with Deteriorated Credit Quality | 60-89 Days Past Due | Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	0		0
Receivables Acquired with Deteriorated Credit Quality | 90 Days or More Past Due | Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Past Due	$ 0		$ 648

[1] Total recorded investment in loans includes $6,085 in accrued interest.

[2] Total recorded investment in loans includes $6,085 in accrued interest.

[3] Total recorded investment in loans includes $5,778 in accrued interest.

[4] Total recorded investment in loans includes $5,778 in accrued interest.