v3.25.4
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Derivative gain (loss) recognized/reclassified) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]      
Amount of gain/(loss) reclassified from AOCI into income $ (55) $ (86) $ (145)
Gains to be reclassified within the next 12 months into interest income 29 63  
Deferred loss in OCI 37    
Derivatives designated as hedges      
Derivative Instruments, Gain (Loss) [Line Items]      
Effective portion of derivative gain/(loss) deferred in AOCI 7 (4)  
Amount of gain/(loss) reclassified from AOCI into income (65) (118)  
Interest on fair value hedges 41 80  
Hedge ineffectiveness / AOCI reclass due to missed forecast 0 (1)  
Derivatives designated as hedges | Cash Flow Hedging      
Derivative Instruments, Gain (Loss) [Line Items]      
Terminated or redesignated, unamortized basis adjustments 3 3  
Derivatives designated as hedges | Cash Flow Hedging | Hedges of floating-rate assets      
Derivative Instruments, Gain (Loss) [Line Items]      
Effective portion of derivative gain/(loss) deferred in AOCI 7 (8)  
Amount of gain/(loss) reclassified from AOCI into income (66) (126)  
Interest on fair value hedges 0 0  
Hedge ineffectiveness / AOCI reclass due to missed forecast 0 0  
Derivatives designated as hedges | Cash Flow Hedging | Hedges of floating-rate liabilities      
Derivative Instruments, Gain (Loss) [Line Items]      
Effective portion of derivative gain/(loss) deferred in AOCI 0 4  
Amount of gain/(loss) reclassified from AOCI into income 1 8  
Interest on fair value hedges 0 0  
Hedge ineffectiveness / AOCI reclass due to missed forecast 0 0  
Derivatives designated as hedges | Fair Value Hedging      
Derivative Instruments, Gain (Loss) [Line Items]      
Terminated or redesignated, unamortized basis adjustments 32 39  
Derivatives designated as hedges | Fair Value Hedging | Hedges of fixed-rate assets      
Derivative Instruments, Gain (Loss) [Line Items]      
Effective portion of derivative gain/(loss) deferred in AOCI 0 0  
Amount of gain/(loss) reclassified from AOCI into income 0 0  
Interest on fair value hedges (11) 88  
Hedge ineffectiveness / AOCI reclass due to missed forecast 0 (1)  
Derivatives designated as hedges | Fair Value Hedging | Hedges of fixed-rate liabilities      
Derivative Instruments, Gain (Loss) [Line Items]      
Effective portion of derivative gain/(loss) deferred in AOCI 0 0  
Amount of gain/(loss) reclassified from AOCI into income 0 0  
Interest on fair value hedges 52 (8)  
Hedge ineffectiveness / AOCI reclass due to missed forecast $ 0 $ 0