Loans and Allowance for Credit Losses - Schedule of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	$ 11,444,216	$ 11,650,350
Add: Unearned income	(9,611)	(26,259)
Total	11,434,605	11,624,091
Loans held for sale	54,119	34,264
Total loans held for investment	11,488,724	11,658,355
Total commercial loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	7,062,565	7,198,302
Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	570,749	552,676
Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	1,761,287	1,874,906
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	4,730,529	4,770,720
Commercial real estate | Non-owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	3,150,269	3,197,765
Commercial real estate | Owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	1,580,260	1,572,955
Total residential and consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	4,381,651	4,452,048
Residential real estate | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	3,321,101	3,105,760
Residential real estate | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	410,845	349,011
Consumer | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance		349,011
Consumer | Consumer credit card
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	98,310	93,825
Consumer | Other consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total unpaid principal balance	$ 551,395	$ 903,452