v3.25.2
Borrowed Funds (FHLB Borrowings, Senior Debt and Subordinated Debt) (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Debt Instrument [Line Items]    
Carrying value of debt $ 57,240 $ 58,601
Parent Company    
Debt Instrument [Line Items]    
Carrying value of debt 32,106 28,352
Parent Company | Senior debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 31,094 27,369
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]    
Interest rate 4.63%  
Carrying value of debt $ 806 777
Parent Company | Junior subordinated debt    
Debt Instrument [Line Items]    
Interest rate 5.16%  
Carrying value of debt $ 206 206
Subsidiaries    
Debt Instrument [Line Items]    
Carrying value of debt 25,134 30,249
Subsidiaries | Senior debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 4,656 5,128
Subsidiaries | Senior debt | Minimum    
Debt Instrument [Line Items]    
Interest rate 3.10%  
Subsidiaries | Senior debt | Maximum    
Debt Instrument [Line Items]    
Interest rate 4.89%  
Subsidiaries | Subordinated debt    
Debt Instrument [Line Items]    
Carrying value of debt $ 2,478 3,121
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 $ 18,000 $ 22,000
Subsidiaries | FHLB | Minimum    
Debt Instrument [Line Items]    
Interest rate 4.73%  
Subsidiaries | FHLB | Maximum    
Debt Instrument [Line Items]    
Interest rate 4.98%