v3.25.2
Commitments And Contingent Liabilities (Narrative) (Details) - USD ($)
$ in Thousands
9 Months Ended
Jun. 30, 2025
Sep. 30, 2024
Minimum    
Unfunded And Commitments To Originate [Line Items]    
Fixed expiration of commitments to extend credit (in days) 60 days  
Maximum    
Unfunded And Commitments To Originate [Line Items]    
Fixed expiration of commitments to extend credit (in days) 360 days  
Unfunded Commitments, Equity Lines of Credit Including Suspended Accounts    
Unfunded And Commitments To Originate [Line Items]    
Unfunded commitments on home equity lines of credit (including commitments for suspended accounts) $ 5,557,905  
Loan Sale Commitments | Residential Mortgage    
Unfunded And Commitments To Originate [Line Items]    
Contractual Obligation 73,300 $ 17,411
Unfunded Loan Commitment    
Unfunded And Commitments To Originate [Line Items]    
Unfunded commitments on home equity lines of credit (including commitments for suspended accounts) 5,521,782  
Unfunded Loan Commitment | Home Equity Line of Credit    
Unfunded And Commitments To Originate [Line Items]    
Unfunded commitments on home equity lines of credit (including commitments for suspended accounts) $ 5,515,011  
Unfunded Loan Commitment | Home Equity Line of Credit | Maximum    
Unfunded And Commitments To Originate [Line Items]    
Home equity unfunded commitments expiration period, years 10 years  
Loan Purchase Commitments | Residential Mortgage    
Unfunded And Commitments To Originate [Line Items]    
Contractual Obligation $ 115,804 $ 15,891