Loans (Risk Category of Loans) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	$ 1,059,619	$ 1,008,678
Loans Acquired With Deteriorated Credit Quality	8,624	10,877
Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	339,597	336,307
Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	531,547	489,796
Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	188,475	182,575
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	996,681	931,366
Loans Acquired With Deteriorated Credit Quality	3,180	319
Pass [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	314,037	307,997
Pass [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	497,670	446,639
Pass [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	184,974	176,730
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	33,922	38,634
Loans Acquired With Deteriorated Credit Quality	816	3,220
Special Mention [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	13,936	14,441
Special Mention [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	17,380	21,338
Special Mention [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	2,606	2,855
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	29,016	38,678
Loans Acquired With Deteriorated Credit Quality	4,628	7,338
Substandard [Member] | Commercial and Industrial Loans and Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	11,624	13,869
Substandard [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	16,497	21,819
Substandard [Member] | Agricultural Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	895	2,990
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