v3.26.1
Derivatives - Schedule of Derivatives Associated with Interest Rate Risk Management Activities (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Customer interest rate contracts    
Derivative Instruments, Gain (Loss) [Line Items]    
Notional $ 4,117 $ 4,301
Assets 6 22
Liabilities 121 104
Customer interest rate contracts | Customer Interest Rate Contracts Hedging  | Hedging Instruments and Hedged Items:     
Derivative Instruments, Gain (Loss) [Line Items]    
Notional 8,277 7,851
Assets 13 43
Liabilities 215 185
Offsetting upstream interest rate contracts    
Derivative Instruments, Gain (Loss) [Line Items]    
Notional 4,306 4,446
Assets 86 70
Liabilities 6 22
Offsetting upstream interest rate contracts | Customer Interest Rate Contracts Hedging  | Hedging Instruments and Hedged Items:     
Derivative Instruments, Gain (Loss) [Line Items]    
Notional 8,277 8,151
Assets 214 184
Liabilities $ 13 $ 43