Loans (Collateral-dependent Loans by Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 3,270,934		$ 3,081,973
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	18,821
Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	944
Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	744
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2,645
Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	23,154
Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	795,688	$ 534,692	589,758
Commercial and Industrial Loans | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	5,311
Commercial and Industrial Loans | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	940
Commercial and Industrial Loans | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	744
Commercial and Industrial Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	965
Commercial and Industrial Loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	7,960
Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,473,234	1,500,247	1,495,862
Commercial Real Estate Loans | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	8,937
Commercial Real Estate Loans | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Commercial Real Estate Loans | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Commercial Real Estate Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,667
Commercial Real Estate Loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	10,604
Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	373,483	384,654	384,526
Agricultural Loans | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,125
Agricultural Loans | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Agricultural Loans | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Agricultural Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3
Agricultural Loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3,128
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	56,728	57,257
Leases | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Leases | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Leases | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Leases | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Leases | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	216,366	225,790	225,755
Home Equity Loans | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	464
Home Equity Loans | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Home Equity Loans | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Home Equity Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Home Equity Loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	464
Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	64,972	69,264	81,217
Consumer Loans | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	41
Consumer Loans | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	4
Consumer Loans | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Consumer Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	10
Consumer Loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	55
Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	10,217	11,953
Credit Cards | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Credit Cards | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Credit Cards | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Credit Cards | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Credit Cards | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	280,246	$ 305,002	$ 304,855
Residential Mortgage Loans | Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	943
Residential Mortgage Loans | Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Residential Mortgage Loans | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Residential Mortgage Loans | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0
Residential Mortgage Loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 943