v3.26.3
ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Schedule of Changes in Components of AOCI, Net of Income Taxes (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance, shareholders' equity $ 21,900 $ 22,296 $ 22,238 $ 22,228
AOCI activity before reclassifications     (874) 404
Amounts reclassified from AOCI to earnings     (5) (3)
Other comprehensive income (loss) for the period (566) 70 (879) 401
Ending balance, shareholders' equity 21,577 21,986 21,577 21,986
Total accumulated other comprehensive (loss) income        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance, shareholders' equity (230) (114) 83 (445)
Other comprehensive income (loss) for the period (566) 70 (879) 401
Ending balance, shareholders' equity (796) (44) (796) (44)
Unrealized loss on securities available for sale        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance, shareholders' equity     (137) (584)
AOCI activity before reclassifications     (788) 400
Amounts reclassified from AOCI to earnings     (1) 0
Other comprehensive income (loss) for the period     (789) 400
Ending balance, shareholders' equity (926) (184) (926) (184)
Unrealized loss on securities available for sale transferred to held to maturity        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance, shareholders' equity     (4) (4)
AOCI activity before reclassifications     0 0
Amounts reclassified from AOCI to earnings 0 0 0 0
Other comprehensive income (loss) for the period     0 0
Ending balance, shareholders' equity (4) (4) (4) (4)
Defined benefit pension items        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance, shareholders' equity     210 135
AOCI activity before reclassifications     (4) (4)
Amounts reclassified from AOCI to earnings     (1) 0
Other comprehensive income (loss) for the period 0 (1) (5) (4)
Ending balance, shareholders' equity 205 131 205 131
Unrealized gain (loss) on cash flow hedge derivatives        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning balance, shareholders' equity     14 8
AOCI activity before reclassifications (48) (1) (82) 8
Amounts reclassified from AOCI to earnings (1) 0 (3) (3)
Other comprehensive income (loss) for the period (49) (1) (85) 5
Ending balance, shareholders' equity $ (71) $ 13 $ (71) $ 13