v3.26.1
Loans and Allowance for Loan Losses - Schedule of Current, Accruing Past Due, and Non-Accrual Loans on an Amortized Cost Basis by Loan Portfolio Class (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Jun. 30, 2025
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis $ 146 $ 54
Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 63 54
Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0 0
Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0 0
Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 83 0
Total commercial and industrial    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 92  
Total commercial and industrial | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 51  
Total commercial and industrial | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial and industrial | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial and industrial | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 41  
Total commercial and industrial | Commercial, financial and agricultural    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 90 20
Total commercial and industrial | Commercial, financial and agricultural | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 49 20
Total commercial and industrial | Commercial, financial and agricultural | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0 0
Total commercial and industrial | Commercial, financial and agricultural | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0 0
Total commercial and industrial | Commercial, financial and agricultural | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 41 0
Total commercial and industrial | Owner-occupied    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 2  
Total commercial and industrial | Owner-occupied | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 2  
Total commercial and industrial | Owner-occupied | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial and industrial | Owner-occupied | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial and industrial | Owner-occupied | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial real estate    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 47  
Total commercial real estate | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 9  
Total commercial real estate | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial real estate | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total commercial real estate | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 38  
Total commercial real estate | Investment properties    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 47 34
Total commercial real estate | Investment properties | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 9 34
Total commercial real estate | Investment properties | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0 0
Total commercial real estate | Investment properties | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0 0
Total commercial real estate | Investment properties | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 38 $ 0
Total consumer    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 7  
Total consumer | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 3  
Total consumer | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total consumer | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total consumer | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 4  
Total consumer | Consumer mortgages    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 6  
Total consumer | Consumer mortgages | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 2  
Total consumer | Consumer mortgages | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total consumer | Consumer mortgages | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total consumer | Consumer mortgages | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 4  
Total consumer | Other consumer loans    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 1  
Total consumer | Other consumer loans | Current    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 1  
Total consumer | Other consumer loans | Accruing 30-89 Days Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total consumer | Other consumer loans | Accruing 90 Days or Greater Past Due    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis 0  
Total consumer | Other consumer loans | Non-accrual    
Financing Receivable, Modified [Line Items]    
Amortized cost basis of loans, aging analysis $ 0