Loans - Collateral-dependent Loans by Class (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 3,893,573	$ 3,788,645
Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	598,893	620,106
Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,076,962	1,966,884
Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	398,109	417,413
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	66,999	56,396
Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	286,880	279,748
Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	88,976	79,904
Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	20,144	17,512
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	356,610	350,682
Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	23,502	28,459
Total | Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	9,911	9,420
Total | Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	8,367	12,228
Total | Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,893	5,262
Total | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Total | Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	475	467
Total | Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	9	22
Total | Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Total | Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	847	1,060
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	15,564	20,749
Real Estate | Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,070	2,078
Real Estate | Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	8,367	12,192
Real Estate | Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,796	4,944
Real Estate | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Real Estate | Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	475	467
Real Estate | Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	9	8
Real Estate | Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Real Estate | Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	847	1,060
Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,231	1,575
Equipment | Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	134	1,219
Equipment | Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	36
Equipment | Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,097	318
Equipment | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Equipment | Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Equipment | Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	2
Equipment | Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Equipment | Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	272
Accounts Receivable | Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	272
Accounts Receivable | Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable | Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable | Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable | Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable | Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Accounts Receivable | Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6,707	5,863
Other | Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6,707	5,851
Other | Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Other | Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Other | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Other | Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Other | Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	12
Other | Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Other | Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 0	$ 0