Loans - Components of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 3,978,919	$ 3,977,900
Less: Unearned Income	(7,009)	(6,818)
Allowance for Credit Losses	(43,754)	(43,765)	$ (44,315)	$ (44,168)
Loans, Net	3,928,156	3,927,317
Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	572,666	589,541
Allowance for Credit Losses	(7,266)	(7,921)	(13,572)	(13,749)
Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,148,808	2,121,835
Allowance for Credit Losses	(26,452)	(25,923)	(22,062)	(21,598)
Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	400,733	423,803
Allowance for Credit Losses	(3,650)	(3,837)	(3,887)	(4,188)
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	73,496	71,988
Allowance for Credit Losses	(373)	(346)	(227)	(209)
Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	312,859	299,685
Allowance for Credit Losses	(2,001)	(1,834)	(1,415)	(1,344)
Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	88,008	87,853
Allowance for Credit Losses	(785)	(759)	(609)	(595)
Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	21,113	20,351
Allowance for Credit Losses	(395)	(383)	(263)	(257)
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	361,236	362,844
Allowance for Credit Losses	(2,832)	(2,762)	$ (2,280)	$ (2,228)
Commercial: | Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	572,666	589,541
Commercial: | Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,148,808	2,121,835
Commercial: | Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	400,733	423,803
Commercial: | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	73,496	71,988
Retail: | Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	312,859	299,685
Retail: | Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	88,008	87,853
Retail: | Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	21,113	20,351
Retail: | Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 361,236	$ 362,844