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ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Pretax | $ (575) | $ (637)
Income Taxes | 130 | 146
Net of Income Taxes | (445) | (491)
Unrealized loss on securities available for sale |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Pretax | (762) | (752)
Income Taxes | 178 | 175
Net of Income Taxes | (584) | (577)
Unrealized loss on securities available for sale transferred to held to maturity |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Pretax | (6) | (7)
Income Taxes | 2 | 2
Net of Income Taxes | (4) | (5)
Defined benefit pension items |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Pretax | 182 | 122
Income Taxes | (47) | (31)
Net of Income Taxes | 135 | 91
Unrealized gain on cash flow hedge derivatives |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |
Pretax | 11 | 0
Income Taxes | (3) | 0
Net of Income Taxes | $ 8 | $ 0

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