Loans (Schedule of Carrying Amount of Loans with Deterioration of Credit Quality) (Details) - USD ($) $ in Thousands	Jun. 30, 2019		Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 2,732,452	[1]	$ 2,744,042	[2]
Commercial and Industrial Loans and Leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total	555,935	[1]	545,342	[2]
Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,216,906	[1]	1,211,882	[2]
Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	368,912	[1]	370,694	[2]
Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	204,350	[1]	209,009	[2]
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	308,525	[1]	329,354	[2]
Loans Acquired With Deteriorated Credit Quality
Financing Receivable, Credit Quality Indicator [Line Items]
Total	10,029		11,556
Carrying Amount, Net of Allowance	9,626		11,548
Loans Acquired With Deteriorated Credit Quality | Commercial and Industrial Loans and Leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total	882		1,038
Loans Acquired With Deteriorated Credit Quality | Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,629		6,993
Loans Acquired With Deteriorated Credit Quality | Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,882		1,877
Loans Acquired With Deteriorated Credit Quality | Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	368		365
Loans Acquired With Deteriorated Credit Quality | Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,268		$ 1,283

[1] Total recorded investment in loans includes $11,778 in accrued interest.

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