v3.26.1
BORROWINGS - Schedule of Long-term Borrowings (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2026
Jun. 24, 2026
Mar. 03, 2026
Dec. 31, 2025
Debt Instrument [Line Items]        
Capital lease obligations $ 85     $ 72
Total long-term borrowings $ 32,036     35,784
Fixed-to-Floating Senior Notes at 5.097% | Subordinated Debt        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate   5.097%    
Parent | Fixed-to-Floating Senior Notes at 5.231% | Senior Notes        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 5.231%      
Interest Rate After Reset 1.41%      
Long-term debt, gross $ 491     497
Parent | Fixed-to-Floating Senior Notes at 4.869% | Senior Notes        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 4.869%      
Interest Rate After Reset 1.487%      
Long-term debt, gross $ 489     0
Parent | Fixed-to-Floating Senior Notes at 4.869% | Subordinated Debt        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate     4.869%  
Parent | Fixed Rate Reset Subordinated Notes at 5.600% | Subordinated Debt        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 5.60%      
Interest Rate After Reset 1.85%      
Long-term debt, gross $ 589     597
Parent | Fixed-to-Fixed Subordinated Notes at 6.254% | Subordinated Debt        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 6.254%      
Interest Rate After Reset 1.97%      
Long-term debt, gross $ 732     745
Subsidiaries | Fixed-to-Floating Senior Notes at 5.097% | Senior Notes        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 5.097%      
Interest Rate After Reset 1.146%      
Long-term debt, gross $ 746     0
Subsidiaries | Fixed Senior Notes at 6.000% | Senior Notes        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 6.00%      
Long-term debt, gross $ 58     58
Subsidiaries | Fixed Subordinated Notes at 6.125% | Subordinated Debt        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 6.125%      
Long-term debt, gross $ 423     430
Subsidiaries | Purchase Money Note to FDIC fixed at 3.500% | Secured Debt        
Debt Instrument [Line Items]        
Debt instrument, stated interest rate 3.50%      
Long-term debt, gross $ 28,423     33,385
Debt instrument, unamortized discount $ 77     $ 115