Loans (Schedule of Risk Category of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	$ 1,523,370	[1],[2]	$ 1,457,768	[3],[4]
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	405,920	[1]	380,851	[3]
Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	601,996	[1]	584,426	[3]
Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	239,672	[1]	219,640	[3]
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	1,175,347		1,112,028
Pass | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	377,189		351,250
Pass | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	565,396		545,804
Pass | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	232,762		214,974
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	47,370		46,019
Special Mention | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	16,682		18,387
Special Mention | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	23,879		23,421
Special Mention | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	6,809		4,211
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	24,871		26,870
Substandard | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	12,049		11,214
Substandard | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	12,721		15,201
Substandard | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	101		455
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Doubtful | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Doubtful | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Doubtful | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	0		0
Total
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	1,247,588		1,184,917
Total | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	405,920		380,851
Total | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	601,996		584,426
Total | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans and leases	239,672		219,640
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	6,924		8,361
Receivables Acquired with Deteriorated Credit Quality | Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	674		354
Receivables Acquired with Deteriorated Credit Quality | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	5,376		6,385
Receivables Acquired with Deteriorated Credit Quality | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	0		0
Receivables Acquired with Deteriorated Credit Quality | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	926		651
Receivables Acquired with Deteriorated Credit Quality | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	1,723		1,697
Receivables Acquired with Deteriorated Credit Quality | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	3,401		4,391
Receivables Acquired with Deteriorated Credit Quality | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	0		0
Receivables Acquired with Deteriorated Credit Quality | Total
Financing Receivable, Recorded Investment [Line Items]
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)	$ 6,050		$ 6,739

[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.