Loans and Allowance for Credit Losses - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	$ 3,578,719	$ 3,565,023
ACL Allocation	56,601	58,204	$ 52,950	$ 50,940
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	30,760,000	31,305
Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	135
Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	30,760,000	31,440
ACL Allocation	189,000	175
Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	487	418	783	674
Agricultural \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	1,877,000	2,135
Agricultural \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	135
Agricultural \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	1,877,000	2,270
ACL Allocation	85,000	0
Commercial and financial
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	10,862	11,890	10,901	10,217
Commercial and financial \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	4,148,000	3,810
Commercial and financial \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Commercial and financial \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	4,148,000	3,810
ACL Allocation	0	0
Construction, 1 to 4 family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	761	617	322	280
Construction, 1 to 4 family residential \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	421,000	51
Construction, 1 to 4 family residential \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Construction, 1 to 4 family residential \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	421,000	51
ACL Allocation	0	0
Construction, land development and commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	3,485	3,165	2,145	2,113
Construction, land development and commercial \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	1,601,000	3,294
Construction, land development and commercial \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Construction, land development and commercial \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	1,601,000	3,294
ACL Allocation	0	0
Mortgage, farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	1,930	2,478	3,469	3,252
Mortgage, farmland \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	5,229,000	3,125
Mortgage, farmland \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Mortgage, farmland \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	5,229,000	3,125
ACL Allocation	21,000	0
Mortgage, 1 to 4 family first liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	20,974	20,959	18,639	18,210
Mortgage, 1 to 4 family first liens \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	11,211,000	10,900
Mortgage, 1 to 4 family first liens \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Mortgage, 1 to 4 family first liens \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	11,211,000	10,900
ACL Allocation	0	0
Mortgage, commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	9,251	9,855	8,137	7,525
Mortgage, commercial \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	4,149,000	3,799
Mortgage, commercial \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Mortgage, commercial \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	4,149,000	3,799
ACL Allocation	83,000	0
Mortgage, 1 to 4 family junior liens
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	5,517	5,639	4,642	4,719
Mortgage, 1 to 4 family junior liens \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	154,000	251
Mortgage, 1 to 4 family junior liens \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Mortgage, 1 to 4 family junior liens \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	154,000	251
ACL Allocation	0	0
Mortgage, multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	2,358	2,345	2,930	2,828
Mortgage, multi-family \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	1,970,000	3,765
Mortgage, multi-family \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Mortgage, multi-family \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	1,970,000	3,765
ACL Allocation	0	0
Loans to individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL Allocation	964	826	$ 970	$ 1,109
Loans to individuals \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	175
Loans to individuals \| Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	0
Loans to individuals \| Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost basis of collateral dependent loans	0	175
ACL Allocation	$ 0	$ 175