Allowance for Credit Losses - Aging By Loan Class (Details) $ in Thousands	Sep. 30, 2024 USD ($) loan	Dec. 31, 2023 USD ($)
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	$ 23,827	$ 5,597
Loans	8,587,025	8,058,961
Current
Financing receivable recorded investment
Loans	8,447,590	7,995,156
Total Past Due
Financing receivable recorded investment
Loans	139,435	63,805
30 to 59 Days
Financing receivable recorded investment
Loans	17,542	12,872
60 to 89 Days
Financing receivable recorded investment
Loans	12,366	5,195
90 Days or Greater
Financing receivable recorded investment
Loans	$ 109,527	45,738
Commercial real estate: farmland & commercial
Financing receivable recorded investment
Number of loans downgraded | loan	1
Number of Loans Secured by Hotel | loan	1
Commercial real estate: multifamily
Financing receivable recorded investment
Number of loans downgraded | loan	2
Number of loans placed on non-accrual | loan	2
Commercial, financial and agricultural
Financing receivable recorded investment
Loans	$ 4,922,980	4,802,622
Commercial, financial and agricultural | Domestic | Commercial
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	3,131	539
Loans	1,692,462	1,628,230
Commercial, financial and agricultural | Domestic | Commercial | Current
Financing receivable recorded investment
Loans	1,684,001	1,594,022
Commercial, financial and agricultural | Domestic | Commercial | Total Past Due
Financing receivable recorded investment
Loans	8,461	34,208
Commercial, financial and agricultural | Domestic | Commercial | 30 to 59 Days
Financing receivable recorded investment
Loans	3,723	2,387
Commercial, financial and agricultural | Domestic | Commercial | 60 to 89 Days
Financing receivable recorded investment
Loans	1,319	1,583
Commercial, financial and agricultural | Domestic | Commercial | 90 Days or Greater
Financing receivable recorded investment
Loans	3,419	30,238
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	15,682	4
Loans	2,911,587	2,793,553
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | Current
Financing receivable recorded investment
Loans	2,836,615	2,791,665
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | Total Past Due
Financing receivable recorded investment
Loans	74,972	1,888
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | 30 to 59 Days
Financing receivable recorded investment
Loans	1,780	1,424
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | 60 to 89 Days
Financing receivable recorded investment
Loans	7,199	371
Commercial, financial and agricultural | Domestic | Commercial real estate: farmland & commercial | 90 Days or Greater
Financing receivable recorded investment
Loans	65,993	93
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	172
Loans	318,931	380,839
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | Current
Financing receivable recorded investment
Loans	293,580	380,140
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | Total Past Due
Financing receivable recorded investment
Loans	25,351	699
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | 30 to 59 Days
Financing receivable recorded investment
Loans	115	369
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | 60 to 89 Days
Financing receivable recorded investment
Loans		330
Commercial, financial and agricultural | Domestic | Commercial real estate: multifamily | 90 Days or Greater
Financing receivable recorded investment
Loans	25,236
Real Estate - construction
Financing receivable recorded investment
Loans	2,457,144	2,091,622
Real Estate - construction | Domestic | Commercial Real Estate: other construction and land development
Financing receivable recorded investment
Loans	2,457,144	2,091,622
Real Estate - construction | Domestic | Commercial Real Estate: other construction and land development | Current
Financing receivable recorded investment
Loans	2,443,045	2,077,917
Real Estate - construction | Domestic | Commercial Real Estate: other construction and land development | Total Past Due
Financing receivable recorded investment
Loans	14,099	13,705
Real Estate - construction | Domestic | Commercial Real Estate: other construction and land development | 30 to 59 Days
Financing receivable recorded investment
Loans	4,147	3,460
Real Estate - construction | Domestic | Commercial Real Estate: other construction and land development | 90 Days or Greater
Financing receivable recorded investment
Loans	9,952	10,245
Real estate - mortgage
Financing receivable recorded investment
Loans	983,211	938,901
Real estate - mortgage | Domestic | Residential First Lien
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	3,019	2,437
Loans	514,227	478,032
Real estate - mortgage | Domestic | Residential First Lien | Current
Financing receivable recorded investment
Loans	505,222	472,236
Real estate - mortgage | Domestic | Residential First Lien | Total Past Due
Financing receivable recorded investment
Loans	9,005	5,796
Real estate - mortgage | Domestic | Residential First Lien | 30 to 59 Days
Financing receivable recorded investment
Loans	3,785	1,812
Real estate - mortgage | Domestic | Residential First Lien | 60 to 89 Days
Financing receivable recorded investment
Loans	2,116	1,439
Real estate - mortgage | Domestic | Residential First Lien | 90 Days or Greater
Financing receivable recorded investment
Loans	3,104	2,545
Real estate - mortgage | Domestic | Residential Junior Lien
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	1,458	1,701
Loans	468,984	460,869
Real estate - mortgage | Domestic | Residential Junior Lien | Current
Financing receivable recorded investment
Loans	464,881	457,282
Real estate - mortgage | Domestic | Residential Junior Lien | Total Past Due
Financing receivable recorded investment
Loans	4,103	3,587
Real estate - mortgage | Domestic | Residential Junior Lien | 30 to 59 Days
Financing receivable recorded investment
Loans	959	1,273
Real estate - mortgage | Domestic | Residential Junior Lien | 60 to 89 Days
Financing receivable recorded investment
Loans	1,686	613
Real estate - mortgage | Domestic | Residential Junior Lien | 90 Days or Greater
Financing receivable recorded investment
Loans	1,458	1,701
Consumer
Financing receivable recorded investment
Loans	48,329	45,121
Consumer | Domestic
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	26	27
Loans	48,329	45,121
Consumer | Domestic | Current
Financing receivable recorded investment
Loans	47,964	44,820
Consumer | Domestic | Total Past Due
Financing receivable recorded investment
Loans	365	301
Consumer | Domestic | 30 to 59 Days
Financing receivable recorded investment
Loans	293	263
Consumer | Domestic | 60 to 89 Days
Financing receivable recorded investment
Loans	46	11
Consumer | Domestic | 90 Days or Greater
Financing receivable recorded investment
Loans	26	27
Foreign
Financing receivable recorded investment
Loans	175,361	180,695
Foreign | Foreign
Financing receivable recorded investment
Past due 90 days or Greater and Still Accruing	339	889
Loans	175,361	180,695
Foreign | Foreign | Current
Financing receivable recorded investment
Loans	172,282	177,074
Foreign | Foreign | Total Past Due
Financing receivable recorded investment
Loans	3,079	3,621
Foreign | Foreign | 30 to 59 Days
Financing receivable recorded investment
Loans	2,740	1,884
Foreign | Foreign | 60 to 89 Days
Financing receivable recorded investment
Loans		848
Foreign | Foreign | 90 Days or Greater
Financing receivable recorded investment
Loans	$ 339	$ 889