Loans and Allowance - Summary of Non-Accrual Loans by Loan Class (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	$ 51,502	$ 61,471
Non-Accrual Loans with no Allowance for Credit Losses	5,786
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	16,817	2,329
Non-Accrual Loans with no Allowance for Credit Losses	628
Agricultural land, production and other loans to farmers
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	119	1,012
Non-Accrual Loans with no Allowance for Credit Losses	0
Construction
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	15	123
Non-Accrual Loans with no Allowance for Credit Losses	0
Commercial real estate, non-owner occupied
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	26,176	46,316
Non-Accrual Loans with no Allowance for Credit Losses	3,816
Commercial real estate, owner occupied
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	1,002	3,040
Non-Accrual Loans with no Allowance for Credit Losses	545
Residential
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	5,556	6,517
Non-Accrual Loans with no Allowance for Credit Losses	797
Home equity
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	1,804	2,095
Non-Accrual Loans with no Allowance for Credit Losses	0
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans	13	$ 39
Non-Accrual Loans with no Allowance for Credit Losses	$ 0