v3.26.1
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Derivative Gain (Loss) Recognized/Reclassified) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Derivative Instruments, Gain (Loss) [Line Items]        
Amount of gain/(loss) reclassified from AOCI into income $ 16 $ (15) $ 29 $ (34)
Loss to be reclassified within the next 12 months into interest income     58 45
Deferred losses 19   19  
Derivatives designated as accounting hedges:        
Derivative Instruments, Gain (Loss) [Line Items]        
Effective portion of derivative gain/(loss) deferred in AOCI (31) 2 (60) 8
Amount of gain/(loss) reclassified from AOCI into income (11) (18) (22) (37)
Interest on fair value hedges 3 12 6 22
Derivatives designated as accounting hedges: | Cash Flow Hedging        
Derivative Instruments, Gain (Loss) [Line Items]        
Terminated or redesignated, unamortized basis adjustments, debt 28 36 28 36
Terminated or redesignated, unamortized basis adjustments, assets 2 3 2 3
Derivatives designated as accounting hedges: | Cash Flow Hedging | Hedges of floating-rate assets        
Derivative Instruments, Gain (Loss) [Line Items]        
Effective portion of derivative gain/(loss) deferred in AOCI (31) 2 (60) 8
Amount of gain/(loss) reclassified from AOCI into income (11) (18) (22) (38)
Interest on fair value hedges 0 0 0 0
Derivatives designated as accounting 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 0 0 0
Amount of gain/(loss) reclassified from AOCI into income 0 0 0 1
Interest on fair value hedges 0 0 0 0
Derivatives designated as accounting 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 0 0
Amount of gain/(loss) reclassified from AOCI into income 0 0 0 0
Interest on fair value hedges 5 14 10 27
Derivatives designated as accounting 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 0 0
Amount of gain/(loss) reclassified from AOCI into income 0 0 0 0
Interest on fair value hedges $ (2) $ (2) $ (4) $ (5)