v3.26.3
Commitments and Contingencies - Additional Information (Details) - USD ($)
 9 Months Ended 12 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Loss Contingencies [Line Items]    
Commitments to extend credit, cancelable $ 1,740,000,000 $ 1,420,000,000
Commitment losses 0 0
Capital call lines    
Loss Contingencies [Line Items]    
Commitments to extend credit 209,700,000  
Commercial and industrial loans    
Loss Contingencies [Line Items]    
Commitments to extend credit 572,540,000 519,135,000
Commercial and industrial loans | Maximum    
Loss Contingencies [Line Items]    
Commitments to extend credit 350,000,000.0  
Total commitments to extend credit    
Loss Contingencies [Line Items]    
Commitments to extend credit 2,740,800,000 2,308,044,000
Increase (decrease) in unused commitment to extend credit 432,800,000  
Total commitments to extend credit | Commercial Construction Loans    
Loss Contingencies [Line Items]    
Increase (decrease) in unused commitment to extend credit (40,000,000.0)  
CCBX sold receivable commitment    
Loss Contingencies [Line Items]    
Commitments to extend credit 7,778,833,000 $ 4,170,246,000
CCBX | Total commitments to extend credit | Credit cards    
Loss Contingencies [Line Items]    
Increase (decrease) in unused commitment to extend credit 127,800,000  
CCBX | Total commitments to extend credit | Residential real estate loans    
Loss Contingencies [Line Items]    
Increase (decrease) in unused commitment to extend credit 125,800,000  
CCBX | Total commitments to extend credit | Consumer and other loans:    
Loss Contingencies [Line Items]    
Increase (decrease) in unused commitment to extend credit 136,800,000  
CCBX | Total commitments to extend credit | Commercial And Industrial Capital Call Line Commitments    
Loss Contingencies [Line Items]    
Increase (decrease) in unused commitment to extend credit $ 53,400,000