Loans (Schedule of Carrying Amount of Loans with Deterioration of Credit Quality) (Details) - USD ($) $ in Thousands		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		$ 2,001,415	[1],[2]	$ 1,574,027	[3],[4]
Commercial and Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		458,538	[2]	419,176	[4]
Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		858,030	[2]	620,163	[4]
Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		306,946	[2]	249,699	[4]
Home Equity Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		134,032	[2]	98,167	[4]
Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		60,099	[2]	50,169	[4]
Residential Mortgage Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		183,770	[2]	136,653	[4]
Loans Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		11,048	[2]	7,555	[2]	$ 8,361
Carrying Amount, Net of Allowance		10,943		7,555		8,307
Loans Acquired with Deteriorated Credit Quality | Commercial and Industrial Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		1,656	[2]	1,325	[2]	354
Loans Acquired with Deteriorated Credit Quality | Commercial Real Estate Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		7,688	[2]	5,363	[2]	6,385
Loans Acquired with Deteriorated Credit Quality | Agricultural Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		706	[2]	0	[2]	0
Loans Acquired with Deteriorated Credit Quality | Home Equity Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance	[2]	0		0
Loans Acquired with Deteriorated Credit Quality | Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		53	[2]	0	[2]	118
Loans Acquired with Deteriorated Credit Quality | Residential Mortgage Loans
Financing Receivable, Recorded Investment [Line Items]
Total Ending Loans Balance		$ 945	[2]	$ 867	[2]	$ 1,504

[1] Total recorded investment in loans includes $8,011 in accrued interest.

[2] Total recorded investment in loans includes $8,011 in accrued interest.

[3] Total recorded investment in loans includes $5,952 in accrued interest.

[4] Total recorded investment in loans includes $5,952 in accrued interest.