Loans and Allowance for Credit Losses - Composition of Impaired Loans by Loan Class (Details) $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)
Average Recorded Investment
Impaired loans with no related allowance	$ 8,113
Impaired loans with related allowance	49,003
Total Impaired Loans	57,116
Interest Income Recognized
Impaired loans with no related allowance	148
Impaired loans with related allowance	84
Total Impaired Loans	232
Commercial and industrial loans
Average Recorded Investment
Impaired loans with no related allowance	991
Impaired loans with related allowance	267
Interest Income Recognized
Impaired loans with no related allowance	0
Impaired loans with related allowance	0
Agricultural land, production and other loans to farmers
Average Recorded Investment
Impaired loans with related allowance	589
Interest Income Recognized
Impaired loans with related allowance	0
Commercial real estate, non-owner occupied
Average Recorded Investment
Impaired loans with no related allowance	4,850
Impaired loans with related allowance	44,119
Interest Income Recognized
Impaired loans with no related allowance	145
Impaired loans with related allowance	0
Commercial real estate, owner occupied
Average Recorded Investment
Impaired loans with no related allowance	1,429
Impaired loans with related allowance	1,447
Interest Income Recognized
Impaired loans with no related allowance	0
Impaired loans with related allowance	0
Residential
Average Recorded Investment
Impaired loans with no related allowance	840
Impaired loans with related allowance	2,108
Interest Income Recognized
Impaired loans with no related allowance	3
Impaired loans with related allowance	70
Individuals' loans for household and other personal expenditures
Average Recorded Investment
Impaired loans with no related allowance	3
Interest Income Recognized
Impaired loans with no related allowance	0
Home equity
Average Recorded Investment
Impaired loans with related allowance	473
Interest Income Recognized
Impaired loans with related allowance	$ 14

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5258-111524

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-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

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