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ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Schedule of Changes in Components of AOCI (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning balance, shareholders' equity | $ 22,296 | $ 22,487 | $ 22,228 | $ 21,255
AOCI activity before reclassifications |  |  | 404 | 329
Amounts reclassified from AOCI to earnings |  |  | (3) | 3
Other comprehensive income, net of tax | 70 | 451 | 401 | 332
Ending balance, shareholders' equity | 21,986 | 22,828 | 21,986 | 22,828
Total accumulated other comprehensive loss |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning balance, shareholders' equity | (114) | (610) | (445) | (491)
Other comprehensive income, net of tax | 70 | 451 | 401 | 332
Ending balance, shareholders' equity | (44) | (159) | (44) | (159)
Unrealized loss on securities available for sale |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning balance, shareholders' equity |  |  | (584) | (577)
AOCI activity before reclassifications |  |  | 400 | 325
Amounts reclassified from AOCI to earnings |  |  | 0 | 0
Other comprehensive income, net of tax |  |  | 400 | 325
Ending balance, shareholders' equity | (184) | (252) | (184) | (252)
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) | (5)
AOCI activity before reclassifications |  |  | 0 | 0
Amounts reclassified from AOCI to earnings | 0 | 1 | 0 | 1
Other comprehensive income, net of tax |  |  | 0 | 1
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 |  |  | 135 | 91
AOCI activity before reclassifications |  |  | (4) | (8)
Amounts reclassified from AOCI to earnings |  |  | 0 | 0
Other comprehensive income, net of tax | (1) | 0 | (4) | (8)
Ending balance, shareholders' equity | 131 | 83 | 131 | 83
Unrealized gain on cash flow hedge derivatives |  |  |  |
AOCI Attributable to Parent, Net of Tax [Roll Forward] |  |  |  |
Beginning balance, shareholders' equity |  |  | 8 | 0
AOCI activity before reclassifications | (1) | 10 | 8 | 12
Amounts reclassified from AOCI to earnings | 0 | 2 | (3) | 2
Other comprehensive income, net of tax | (1) | 12 | 5 | 14
Ending balance, shareholders' equity | $ 13 | $ 14 | $ 13 | $ 14

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