Loans and Allowance for Credit Losses - Schedule of Age Analysis of Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	$ 11,541,912	$ 11,444,216
90 Days past due and still accruing	711	1,343
Nonaccrual	51,364	44,663
Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	11,445,545	11,363,135
30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	44,292	35,075
Total commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	7,103,839	7,062,565
90 Days past due and still accruing	38	34
Nonaccrual	23,033	17,211
Total commercial loans | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	7,064,577	7,035,370
Total commercial loans | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	16,191	9,950
Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	512,681	570,749
90 Days past due and still accruing	0	0
Nonaccrual	77	81
Construction and development | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	512,330	570,668
Construction and development | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	274	0
Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,740,689	1,761,287
90 Days past due and still accruing	38	34
Nonaccrual	10,282	5,581
Commercial, financial & agricultural | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,726,479	1,751,575
Commercial, financial & agricultural | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,890	4,097
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,850,469	4,730,529
90 Days past due and still accruing	0	0
Nonaccrual	12,674	11,549
Commercial real estate | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,825,768	4,713,127
Commercial real estate | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	12,027	5,853
Commercial real estate | Non-owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,267,008	3,150,269
90 Days past due and still accruing	0	0
Nonaccrual	9,408	9,007
Commercial real estate | Non-owner occupied CRE | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,249,170	3,137,206
Commercial real estate | Non-owner occupied CRE | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	8,430	4,056
Commercial real estate | Owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,583,461	1,580,260
90 Days past due and still accruing	0	0
Nonaccrual	3,266	2,542
Commercial real estate | Owner occupied CRE | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,576,598	1,575,921
Commercial real estate | Owner occupied CRE | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,597	1,797
Residential real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,423,146	3,321,101
90 Days past due and still accruing	205	862
Nonaccrual	24,335	23,893
Residential real estate | Residential mortgage loans | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,380,559	3,283,403
Residential real estate | Residential mortgage loans | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	18,047	12,943
Residential real estate | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	422,737	410,845
90 Days past due and still accruing	125	167
Nonaccrual	1,237	1,203
Residential real estate | Home equity lines of credit | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	420,147	408,114
Residential real estate | Home equity lines of credit | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,228	1,361
Consumer | Consumer credit card
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	93,171	98,310
90 Days past due and still accruing	343	280
Nonaccrual	0	0
Consumer | Consumer credit card | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	91,960	96,988
Consumer | Consumer credit card | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	868	1,042
Consumer | Other consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	499,019	551,395
90 Days past due and still accruing	0	0
Nonaccrual	2,759	2,356
Consumer | Other consumer loans | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	488,302	539,260
Consumer | Other consumer loans | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	7,958	9,779
Total residential and consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,438,073	4,381,651
90 Days past due and still accruing	673	1,309
Nonaccrual	28,331	27,452
Total residential and consumer loans | Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,380,968	4,327,765
Total residential and consumer loans | 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	$ 28,101	$ 25,125