Loans and Allowance for Loan Losses - Non Accrual Loans and Loans Past Due 90 Days Or More and Still Accruing (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Loan portfolio past due loans
Nonaccrual	$ 2,810	$ 2,823
Total Loans Greater than 90 Days & Accruing	80	3,498
Residential real estate
Loan portfolio past due loans
Nonaccrual	472	578
Total Loans Greater than 90 Days & Accruing	16	69
Commercial and commercial real estate
Loan portfolio past due loans
Nonaccrual	2,174	2,052
Total Loans Greater than 90 Days & Accruing	50	1,240
Agricultural production and real estate
Loan portfolio past due loans
Nonaccrual	158	181
Total Loans Greater than 90 Days & Accruing		2,181
Consumer and margin loans
Loan portfolio past due loans
Nonaccrual	6	12
Total Loans Greater than 90 Days & Accruing	$ 14	$ 8