Past Due Loans, Allowance For Credit Losses, Non-Accrual Loans, and TDRS - TDRs By Class (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	$ 782	$ 813
Non-accrual	7,403	11,703
Total	8,185	12,516	$ 13,294
Eligible modifications, outstanding balance	88,500
Specific reserves related to TDRs	252	140
Commercial, industrial, agricultural | Commercial and industrial
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	0	0
Non-accrual	6,923	8,859
Total	6,923	8,859
Commercial, industrial, agricultural | Agricultural
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	0	0
Non-accrual	0	0
Total	0	0
Commercial real estate
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	164	184
Non-accrual	153	2,500
Total	317	2,684
Commercial real estate | Office, retail, and industrial
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	0	0
Non-accrual	0	2,340
Total	0	2,340
Commercial real estate | Multi- family
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	0	0
Non-accrual	153	160
Total	153	160
Commercial real estate | Construction
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	0	0
Non-accrual	0	0
Total	0	0
Commercial real estate | Other commercial real estate
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	164	184
Non-accrual	0	0
Total	164	184
Total corporate loans
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	164	184
Non-accrual	7,076	11,359
Total	7,240	11,543
Consumer
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	618	629
Non-accrual	327	344
Total	945	973
Consumer | Home equity
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	30	31
Non-accrual	108	116
Total	138	147
Consumer | 1-4 family mortgages
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	588	598
Non-accrual	219	228
Total	807	826
Consumer | Installment
Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Details) - TDRs By Class [Line Items]
Accruing	0	0
Non-accrual	0	0
Total	$ 0	$ 0