Loans (Schedule of Carrying Amount of Loans with Deterioration of Credit Quality) (Details) - USD ($) $ in Thousands	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 3,095,902	[1]	$ 2,744,042	[2]
Commercial and Industrial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	591,403	[1]	545,342	[2]
Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,499,864	[1]	1,211,882	[2]
Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	390,871	[1]	370,694	[2]
Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	226,775	[1]	209,009	[2]
Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	81,429	[1]	77,761	[2]
Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	305,560	[1]	329,354	[2]
Loans Acquired with Deteriorated Credit Quality
Financing Receivable, Credit Quality Indicator [Line Items]
Total	12,798		11,556		$ 9,117
Carrying Amount, Net of Allowance	12,393		11,548		9,106
Loans Acquired with Deteriorated Credit Quality | Commercial and Industrial Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,368		1,038		988
Loans Acquired with Deteriorated Credit Quality | Commercial Real Estate Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	7,212		6,993		6,452
Loans Acquired with Deteriorated Credit Quality | Agricultural Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,161		1,877		789
Loans Acquired with Deteriorated Credit Quality | Home Equity Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	369		365		0
Loans Acquired with Deteriorated Credit Quality | Consumer Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0		0		0
Loans Acquired with Deteriorated Credit Quality | Residential Mortgage Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 688		$ 1,283		$ 888

[1] Total recorded investment in loans includes $13,929 in accrued interest.

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