Loans and Allowance for Credit Losses - Schedule of Amortized Cost Basis of Collateral-Dependent Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	$ 11,541,912	$ 11,444,216
Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	512,681	570,749
Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	1,740,689	1,761,287
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,850,469	4,730,529
Commercial real estate | Non-owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	3,267,008	3,150,269
Commercial real estate | Owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	1,583,461	1,580,260
Residential real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	3,423,146	3,321,101
Residential real estate | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	422,737	410,845
Consumer | Consumer credit card
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	93,171	98,310
Consumer | Other consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	499,019	551,395
Total
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	24,996	20,628
Total | Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	2,099	2,530
Total | Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	8,975	4,404
Total | Commercial real estate | Non-owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	9,429	9,029
Total | Commercial real estate | Owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,030	4,049
Total | Commercial real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans		616
Total | Residential real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	424
Total | Residential real estate | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	39	0
Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	16,021	16,224
Real Estate | Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	2,099	2,530
Real Estate | Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	0
Real Estate | Commercial real estate | Non-owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	9,429	9,029
Real Estate | Commercial real estate | Owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,030	4,049
Real Estate | Commercial real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans		616
Real Estate | Residential real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	424
Real Estate | Residential real estate | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	39	0
Business Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	8,975	4,404
Business Assets | Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	0
Business Assets | Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	8,975	4,404
Business Assets | Commercial real estate | Non-owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	0
Business Assets | Commercial real estate | Owner occupied CRE
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	0
Business Assets | Commercial real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans		0
Business Assets | Residential real estate | Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0
Business Assets | Residential real estate | Home equity lines of credit
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	$ 0	$ 0