Loans and Allowance - Past Due Aging of Loan Portfolio by Loan Class (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans	$ 9,356,241	$ 9,241,861
Loans > 90 Days or More Past Due And Accruing	2,085	963
Current
Financing Receivable, Past Due [Line Items]
Loans	9,304,687	9,207,113
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	28,580	15,006
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	7,780	7,056
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	15,194	12,686
Commercial and industrial loans
Financing Receivable, Past Due [Line Items]
Loans	2,826,660	2,714,565
Loans > 90 Days or More Past Due And Accruing	1,424	675
Commercial and industrial loans | Current
Financing Receivable, Past Due [Line Items]
Loans	2,807,708	2,708,539
Commercial and industrial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	9,181	2,602
Commercial and industrial loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,862	2,437
Commercial and industrial loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,909	987
Agricultural land, production and other loans to farmers
Financing Receivable, Past Due [Line Items]
Loans	209,077	246,442
Loans > 90 Days or More Past Due And Accruing	0	0
Agricultural land, production and other loans to farmers | Current
Financing Receivable, Past Due [Line Items]
Loans	209,050	246,380
Agricultural land, production and other loans to farmers | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	36
Agricultural land, production and other loans to farmers | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Agricultural land, production and other loans to farmers | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	27	26
Construction
Financing Receivable, Past Due [Line Items]
Loans	552,975	523,066
Loans > 90 Days or More Past Due And Accruing	0	0
Construction | Current
Financing Receivable, Past Due [Line Items]
Loans	552,866	522,349
Construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	717
Construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	109	0
Construction | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Commercial real estate, non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,073,197	2,135,459
Loans > 90 Days or More Past Due And Accruing	0	0
Commercial real estate, non-owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	2,057,043	2,124,853
Commercial real estate, non-owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	11,851	3,327
Commercial real estate, non-owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Commercial real estate, non-owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	4,303	7,279
Commercial real estate, owner occupied
Financing Receivable, Past Due [Line Items]
Loans	974,521	986,720
Loans > 90 Days or More Past Due And Accruing	0	0
Commercial real estate, owner occupied | Current
Financing Receivable, Past Due [Line Items]
Loans	973,075	985,785
Commercial real estate, owner occupied | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,182	643
Commercial real estate, owner occupied | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	27	0
Commercial real estate, owner occupied | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	237	292
Residential
Financing Receivable, Past Due [Line Items]
Loans	1,226,695	1,159,127
Loans > 90 Days or More Past Due And Accruing	132	0
Residential | Current
Financing Receivable, Past Due [Line Items]
Loans	1,217,155	1,148,294
Residential | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	3,697	3,979
Residential | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	713	4,255
Residential | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	5,130	2,599
Home equity
Financing Receivable, Past Due [Line Items]
Loans	512,641	523,754
Loans > 90 Days or More Past Due And Accruing	527	288
Home equity | Current
Financing Receivable, Past Due [Line Items]
Loans	507,837	518,643
Home equity | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	2,219	3,327
Home equity | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	999	281
Home equity | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	1,586	1,503
Individuals' loans for household and other personal expenditures
Financing Receivable, Past Due [Line Items]
Loans	147,593	146,092
Loans > 90 Days or More Past Due And Accruing	2	0
Individuals' loans for household and other personal expenditures | Current
Financing Receivable, Past Due [Line Items]
Loans	147,071	145,634
Individuals' loans for household and other personal expenditures | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	450	375
Individuals' loans for household and other personal expenditures | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	70	83
Individuals' loans for household and other personal expenditures | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	2	0
Public finance and other commercial loans
Financing Receivable, Past Due [Line Items]
Loans	832,882	806,636
Loans > 90 Days or More Past Due And Accruing	0	0
Public finance and other commercial loans | Current
Financing Receivable, Past Due [Line Items]
Loans	832,882	806,636
Public finance and other commercial loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Public finance and other commercial loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans	0	0
Public finance and other commercial loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Loans	$ 0	$ 0