Loans (Schedule of Carrying Amount of Loans with Deterioration of Credit Quality) (Details) - USD ($) $ in Thousands	Sep. 30, 2019		Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 3,074,146	[1]	$ 2,744,042	[2]
Commercial and Industrial Loans and Leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total	580,240	[1]	545,342	[2]
Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,481,155	[1]	1,211,882	[2]
Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	393,033	[1]	370,694	[2]
Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	223,658	[1]	209,009	[2]
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	313,427	[1]	329,354	[2]
Loans Acquired With Deteriorated Credit Quality
Financing Receivable, Credit Quality Indicator [Line Items]
Total	14,300		11,556
Carrying Amount, Net of Allowance	13,938		11,548
Loans Acquired With Deteriorated Credit Quality | Commercial and Industrial Loans and Leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,693		1,038
Loans Acquired With Deteriorated Credit Quality | Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	8,938		6,993
Loans Acquired With Deteriorated Credit Quality | Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,611		1,877
Loans Acquired With Deteriorated Credit Quality | Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	371		365
Loans Acquired With Deteriorated Credit Quality | Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 687		$ 1,283

[1] Total recorded investment in loans includes $13,404 in accrued interest.

[2] Total recorded investment in loans includes $12,301 in accrued interest.