Loans and Allowance for Credit Losses - Loans Modified as Troubled Debt Restructurings During Period (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($) Modification	Jun. 30, 2020 USD ($) Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	5	7
Financing Receivables, Modifications during Period, Balance | $	$ 1,098	$ 2,744
Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	2	1
Financing Receivables, Modifications during Period, Balance | $	$ 1,074	$ 303
Real Estate Loan | 1-4 Family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	1	0
Financing Receivables, Modifications during Period, Balance | $	$ 395	$ 0
Commercial Real Estate | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	1	1
Financing Receivables, Modifications during Period, Balance | $	$ 679	$ 303
Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	0	2
Financing Receivables, Modifications during Period, Balance | $	$ 0	$ 88
Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	0	3
Financing Receivables, Modifications during Period, Balance | $	$ 0	$ 2,342
Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivables, Modifications during Period, Number | Modification	3	1
Financing Receivables, Modifications during Period, Balance | $	$ 24	$ 11