Loans and Allowance for Credit Losses - Schedule of Amortized Cost Basis of Collateral-Dependent Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	$ 11,444,216	$ 11,650,350
Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	570,749	552,676
Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	1,761,287	1,874,906
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,730,529	4,770,720
Commercial real estate | Non-owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	3,150,269	3,197,765
Commercial real estate | Owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	1,580,260	1,572,955
Residential real estate | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	3,321,101	3,105,760
Total
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	20,628	15,623
Total | Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	2,530	1,417
Total | Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,404	341
Total | Commercial real estate | Non-owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	9,029	7,239
Total | Commercial real estate | Owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,049	3,800
Total | Residential real estate | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	616	2,824
Real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	16,224	15,576
Real estate | Construction and development
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	2,530	1,417
Real estate | Commercial, financial & agricultural
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	341
Real estate | Commercial real estate | Non-owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	9,029	7,239
Real estate | Commercial real estate | Owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,049	3,800
Real estate | Residential real estate | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	616	2,777
Business assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	4,404	47
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	4,404	0
Business assets | Commercial real estate | Non-owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	0
Business assets | Commercial real estate | Owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	0	0
Business assets | Residential real estate | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Collateral dependent loans	$ 0	$ 47