v3.26.1
Borrowed Funds (FHLB Borrowings, Senior Debt and Subordinated Debt) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Debt Instrument [Line Items]    
Carrying value of debt $ 63,940 $ 54,658
Parent Company    
Debt Instrument [Line Items]    
Carrying value of debt 36,297 33,664
Parent Company | Senior debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 33,789 32,650
Parent Company | Senior debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 1.15%  
Parent Company | Senior debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 6.88%  
Parent Company | Subordinated debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 2,302 808
Parent Company | Subordinated debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 4.63%  
Parent Company | Subordinated debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 5.42%  
Parent Company | Junior subordinated debt    
Debt Instrument [Line Items]    
Interest rate 4.50%  
Carrying value of debt $ 206 206
Subsidiaries    
Debt Instrument [Line Items]    
Carrying value of debt 27,643 20,994
Subsidiaries | Senior debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 4,232 5,992
Subsidiaries | Senior debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 3.10%  
Subsidiaries | Senior debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 4.54%  
Subsidiaries | Subordinated debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 1,994 2,002
Subsidiaries | Subordinated debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 2.70%  
Subsidiaries | Subordinated debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 5.90%  
Subsidiaries | FHLB    
Debt Instrument [Line Items]    
Carrying value of debt $ 21,417 $ 13,000
Subsidiaries | FHLB | Minimum    
Debt Instrument [Line Items]    
Interest rate 3.25%  
Subsidiaries | FHLB | Maximum    
Debt Instrument [Line Items]    
Interest rate 4.22%