LHFI and ACL, LHFI - Aging Analysis of Past Due and Nonaccrual LHFI by Loan Type (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	$ 13,100,111	$ 12,950,524
30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	35,995	40,995
Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	15,091	13,898
Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	28,929	29,322
Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	80,015	84,215
Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	13,020,096	12,866,309
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	614,787	642,886
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	249	93
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	213	507
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	188	2,362
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	650	2,962
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	614,137	639,924
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	647,843	622,397
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	6,054	4,493
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,588	1,687
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	3,748	2,716
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	12,390	8,896
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	635,453	613,501
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,247,163	2,282,318
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	18,517	19,298
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	7,316	9,327
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	14,313	22,164
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	40,146	50,789
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,207,017	2,231,529
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	3,582,552	3,489,434
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,137	1,531
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	3,917	1,063
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	793	727
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	6,847	3,321
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	3,575,705	3,486,113
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	1,475,798	1,312,551
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	518	126
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	0	0
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	28	207
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	546	333
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	1,475,252	1,312,218
Commercial and Industrial Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	1,767,079	1,922,910
Commercial and Industrial Loans [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	4,221	11,881
Commercial and Industrial Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	421	484
Commercial and Industrial Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	9,391	499
Commercial and Industrial Loans [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	14,033	12,864
Commercial and Industrial Loans [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	1,753,046	1,910,046
Other Construction Financing Receivable [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	973,469	867,793
Other Construction Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	60	62
Other Construction Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	0	0
Other Construction Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	0	0
Other Construction Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	60	62
Other Construction Financing Receivable [Member] | Other Loans Secured by Real Estate [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	973,409	867,731
Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	152,611	165,734
Consumer Loans [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	1,788	2,112
Consumer Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	628	772
Consumer Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	448	647
Consumer Loans [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,864	3,531
Consumer Loans [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	149,747	162,203
State and Other Political Subdivision Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	996,002	1,088,466
State and Other Political Subdivision Loans [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	44	152
State and Other Political Subdivision Loans [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	0	0
State and Other Political Subdivision Loans [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	0	0
State and Other Political Subdivision Loans [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	44	152
State and Other Political Subdivision Loans [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	995,958	1,088,314
Other Commercial Loans and Leases [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	642,807	556,035
Other Commercial Loans and Leases [Member] | 30 Days or More Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,407	1,247
Other Commercial Loans and Leases [Member] | Past Due 60 to 89 Days [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	8	58
Other Commercial Loans and Leases [Member] | Past Due 90 Days or More [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	20	0
Other Commercial Loans and Leases [Member] | Financial Asset, Past Due [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	2,435	1,305
Other Commercial Loans and Leases [Member] | Current Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total LHFI	$ 640,372	$ 554,730