Loans and Allowance - Summary of Non-Accrual Loans by Loan Class (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 56,739	$ 15,949
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	5,947	1,255
Agricultural production financing and other loans to farmers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	0	183
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	126	977
Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	43,030	7,007
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	4,914	5,062
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	2,674	1,421
Individuals' loans for household and other personal expenditures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 48	$ 44