v3.26.3
Credit Quality - Schedule of Amortized Cost Basis Payment Status (Detail) - USD ($)
$ in Thousands
Sep. 30, 2026
Sep. 30, 2025
Current [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) $ 9,004 $ 24,922
Current [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 1,244 11,868
Current [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 1,395 11,291
Current [Member] | Other Commercial [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 3,389 1,477
Current [Member] | Residential Real Estate [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 2,976 243
Current [Member] | Construction & Land Development [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 43
Current [Member] | Consumer [Member] | Bankcard [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
Current [Member] | Consumer [Member] | Other Consumer [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
30-89 Days Past Due [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 1,813 4,399
30-89 Days Past Due [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
30-89 Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 1,813 4,399
30-89 Days Past Due [Member] | Other Commercial [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
30-89 Days Past Due [Member] | Residential Real Estate [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
30-89 Days Past Due [Member] | Construction & Land Development [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
30-89 Days Past Due [Member] | Consumer [Member] | Bankcard [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
30-89 Days Past Due [Member] | Consumer [Member] | Other Consumer [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Commercial Real Estate [Member] | Owner-Occupied [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner-Occupied [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Other Commercial [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Residential Real Estate [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Construction & Land Development [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Consumer [Member] | Bankcard [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) 0 0
90+ Days Past Due [Member] | Consumer [Member] | Other Consumer [Member]    
Financing Receivable, Modifications [Line Items]    
Payment Status (Amortized Cost Basis) $ 0 $ 0