Loans and Allowance for Credit Losses - Schedule of Age Analysis of Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	$ 11,683,856	$ 11,444,216
90 Days past due and still accruing	2,026	1,343
Nonaccrual	55,126	44,663
Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	11,603,437	11,363,135
30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	23,267	35,075
Total commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	7,214,522	7,062,565
90 Days past due and still accruing	27	34
Nonaccrual	28,404	17,211
Total commercial loans \| Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	7,177,526	7,035,370
Total commercial loans \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	8,565	9,950
Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	569,593	570,749
90 Days past due and still accruing	0	0
Nonaccrual	314	81
Construction and development \| Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	568,747	570,668
Construction and development \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	532	0
Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,799,584	1,761,287
90 Days past due and still accruing	27	34
Nonaccrual	10,134	5,581
Commercial, financial & agricultural \| Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,788,116	1,751,575
Commercial, financial & agricultural \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,307	4,097
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,845,345	4,730,529
90 Days past due and still accruing	0	0
Nonaccrual	17,956	11,549
Commercial real estate \| Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,820,663	4,713,127
Commercial real estate \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	6,726	5,853
Commercial real estate \| Non-owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,249,479	3,150,269
90 Days past due and still accruing	0	0
Nonaccrual	16,064	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	3,228,311	3,137,206
Commercial real estate \| Non-owner occupied CRE \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	5,104	4,056
Commercial real estate \| Owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,595,866	1,580,260
90 Days past due and still accruing	0	0
Nonaccrual	1,892	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	1,592,352	1,575,921
Commercial real estate \| Owner occupied CRE \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,622	1,797
Residential real estate \| Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	3,475,428	3,321,101
90 Days past due and still accruing	1,649	862
Nonaccrual	23,052	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	3,445,712	3,283,403
Residential real estate \| Residential mortgage loans \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	5,015	12,943
Residential real estate \| Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	433,330	410,845
90 Days past due and still accruing	65	167
Nonaccrual	1,419	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	429,878	408,114
Residential real estate \| Home equity lines of credit \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	1,968	1,361
Consumer \| Consumer credit card
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	98,107	98,310
90 Days past due and still accruing	283	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	97,174	96,988
Consumer \| Consumer credit card \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	650	1,042
Consumer \| Other consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	462,469	551,395
90 Days past due and still accruing	2	0
Nonaccrual	2,251	2,356
Consumer \| Other consumer loans \| Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	453,147	539,260
Consumer \| Other consumer loans \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	7,069	9,779
Total residential and consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,469,334	4,381,651
90 Days past due and still accruing	1,999	1,309
Nonaccrual	26,722	27,452
Total residential and consumer loans \| Current or less than 30 days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	4,425,911	4,327,765
Total residential and consumer loans \| 30 - 89 Days past due
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	$ 14,702	$ 25,125