Loans (Risk Category of Loans) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	$ 1,418,589	[1]	$ 1,390,802	[2]
Loans Acquired with Deteriorated Credit Quality	11,552		14,753
Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	366,919	[1]	351,903	[2]
Loans Acquired with Deteriorated Credit Quality	591		1,981
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	596,114	[1]	583,604	[2]
Loans Acquired with Deteriorated Credit Quality	9,332		10,871
Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	190,368	[1]	195,171	[2]
Loans Acquired with Deteriorated Credit Quality	0		0
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	1,078,421		1,056,827
Loans Acquired with Deteriorated Credit Quality	3,101		3,121
Pass [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	336,728		324,685
Pass [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	556,501		539,533
Pass [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	185,192		192,609
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	46,473		38,010
Loans Acquired with Deteriorated Credit Quality	1,740		661
Special Mention [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	17,930		15,485
Special Mention [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	23,560		20,168
Special Mention [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	4,983		2,357
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	28,507		35,841
Loans Acquired with Deteriorated Credit Quality	5,082		9,070
Substandard [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	12,261		11,733
Substandard [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	16,053		23,903
Substandard [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	193		205
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Loans Acquired with Deteriorated Credit Quality	0		0
Doubtful [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Doubtful [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Doubtful [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Total by Risk Category [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	1,153,401		1,130,678
Loans Acquired with Deteriorated Credit Quality	9,923		12,852
Total by Risk Category [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	366,919		351,903
Total by Risk Category [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	596,114		583,604
Total by Risk Category [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	$ 190,368		$ 195,171

[1] Total recorded investment in loans includes $5,258 in accrued interest.

[2] Total recorded investment in loans includes $5,590 in accrued interest.