v3.26.3
Loans - Narrative (Details)
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Dec. 31, 2023
USD ($)
Jun. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Jun. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing Receivable, Purchased with Credit Deterioration, Discount (Premium) $ 2,000,000.0       $ 200,000        
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available 6,200,000,000   $ 6,200,000,000       $ 6,300,000,000    
Proceeds from sale of SBA loans 0 $ 22,200,000 25,400,000 $ 78,000,000.0          
Gain on sale of SBA loans   $ 1,100,000 1,414,000 $ 4,188,000          
Financing receivable, allowance for credit loss 144,519,000   144,519,000       140,022,000    
Allowance for credit loss adjustment 44,200,000   44,200,000            
Nonperforming loan balances, excluding government guaranteed balances 53,700,000   53,700,000       28,900,000    
Loans, including unearned loan fees 12,200,186,000   12,200,186,000       11,660,316,000    
Financing Receivable, Consumer Mortgage Loan Secured By Residential Real Estate In Process Of Foreclosure, Amount 1,100,000   1,100,000       200,000    
Other Assets                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Accrued interest receivable 63,400,000   63,400,000       58,300,000    
Enterprise Value Lending Portfolio Niche Segment                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Allowance for credit loss adjustment $ 24,800,000   $ 24,800,000            
C&I | Term Extension                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing Receivable, Excluding Accrued Interest, ModFinancing Receivable, Excluding Accrued Interest, Modified, Extension Termified, Outstanding   4 months 9 months 6 months          
C&I | Payment Delay                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing Receivable, Excluding Accrued Interest, ModFinancing Receivable, Excluding Accrued Interest, Modified, Extension Termified, Outstanding 8 months                
Payment Delay, Weighted Average Amount $ 3,471,000   $ 1,739,000            
C&I | Extended maturity and interest rate reduction                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Term Extension, Weighted Average Term     19 months            
Rate Reduction, Weighted Average Interest Rate 0.65%                
Construction and land development | Term Extension                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing Receivable, Excluding Accrued Interest, ModFinancing Receivable, Excluding Accrued Interest, Modified, Extension Termified, Outstanding     4 months            
Commercial - owner occupied | Term Extension                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing Receivable, Excluding Accrued Interest, ModFinancing Receivable, Excluding Accrued Interest, Modified, Extension Termified, Outstanding   3 months 4 months 15 months          
Commercial - owner occupied | Payment Delay                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing Receivable, Excluding Accrued Interest, ModFinancing Receivable, Excluding Accrued Interest, Modified, Extension Termified, Outstanding 6 months                
Commercial - owner occupied | Extended maturity and interest rate reduction                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Term Extension, Weighted Average Term 12 months                
Rate Reduction, Weighted Average Interest Rate 0.96%                
Non-Covered Loans                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing receivable, allowance for credit loss $ 144,519,000 $ 148,854,000 $ 144,519,000 $ 148,854,000   $ 139,238,000 140,022,000 $ 145,133,000 $ 137,950,000
Loans, including unearned loan fees 12,344,705,000   12,344,705,000       11,800,338,000    
Non-Covered Loans | C&I                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing receivable, allowance for credit loss 81,464,000 71,503,000 81,464,000 71,503,000   77,035,000 68,345,000 72,081,000 63,231,000
Loans, including unearned loan fees 5,472,681,000   5,472,681,000       5,236,473,000    
Non-Covered Loans | Construction and land development                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing receivable, allowance for credit loss 13,462,000 13,441,000 13,462,000 13,441,000   11,703,000 11,016,000 12,964,000 9,837,000
Loans, including unearned loan fees 747,202,000   747,202,000       689,357,000    
Non-Covered Loans | Commercial - owner occupied                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing receivable, allowance for credit loss 15,386,000 $ 18,990,000 15,386,000 $ 18,990,000   $ 17,686,000 19,218,000 $ 17,643,000 $ 20,400,000
Loans, including unearned loan fees 2,482,819,000   2,482,819,000       $ 2,460,761,000    
Cumulative Effect, Period Of Adoption, Adjustment | Non-Covered Loans                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Financing receivable, allowance for credit loss $ 11,500,000   $ 11,500,000            
Cumulative Effect, Period Of Adoption, Adjustment | Non-Covered Loans | Baseline                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Growth upside forecast 0.40   0.40            
Cumulative Effect, Period Of Adoption, Adjustment | Non-Covered Loans | Near-term growth upside                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Growth upside forecast 0.30   0.30            
Cumulative Effect, Period Of Adoption, Adjustment | Non-Covered Loans | Moderate recession downside                  
Accounts, Notes, Loans and Financing Receivable [Line Items]                  
Growth upside forecast 0.30   0.30