v3.26.1
Derivative Financial Instruments - Carrying Value of Hedged Items in Fair Value Hedge (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Derivatives, Fair Value [Line Items]    
Carrying amount of hedged items $ 18,748 $ 15,902
Active hedged asset adjustments (999) (966)
Discontinued hedged asset adjustments (410) (204)
Total hedged asset adjustments (1,409) $ (1,170)
Carrying amount of hedged liability items 10,677  
Active hedged liability adjustments (223)  
Discontinued hedged liability adjustments 0  
Total hedged liability adjustments $ (223)  
Hedged Asset, Statement of Financial Position [Extensible Enumeration] Securities available-for-sale (amortized cost of $34.5 billion and $31.7 billion, and includes $0.4 billion and $0.0 billion pledged to creditors) Securities available-for-sale (amortized cost of $34.5 billion and $31.7 billion, and includes $0.4 billion and $0.0 billion pledged to creditors)
Hedged Liability, Statement of Financial Position [Extensible Enumeration] Long-term debt (includes $8.7 billion and $8.3 billion designated under fair value option)  
Balance Sheet Location [Axis]: us-gaap:Deposits    
Derivatives, Fair Value [Line Items]    
Carrying amount of hedged liability items   $ 1,497
Active hedged liability adjustments   (8)
Discontinued hedged liability adjustments   6
Total hedged liability adjustments   $ (2)
Hedged Liability, Statement of Financial Position [Extensible Enumeration]   Deposits
Balance Sheet Location [Axis]: us-gaap:LongTermDebt    
Derivatives, Fair Value [Line Items]    
Carrying amount of hedged liability items   $ 8,825
Active hedged liability adjustments   (74)
Discontinued hedged liability adjustments   0
Total hedged liability adjustments   $ (74)
Hedged Liability, Statement of Financial Position [Extensible Enumeration]   Long-term debt (includes $8.7 billion and $8.3 billion designated under fair value option)