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ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Schedule of Pretax and After-tax Components of Other Comprehensive Income (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, Net of Income Taxes | $ 533 | $ 45 |
Amounts reclassified from AOCI to earnings, Net of Income Taxes | (5) | 1 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Pretax | 709 | 62 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Income Taxes | (181) | (16) |
Other comprehensive income, net of tax | 528 | 46 | $ 244
Unrealized loss on securities available for sale: |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, Pretax | 603 | (10) |
AOCI activity before reclassification, Income Taxes | (154) | 3 |
AOCI activity before reclassification, Net of Income Taxes | 449 | (7) |
Amounts reclassified from AOCI to earnings, Pretax | (3) | 0 |
Amounts reclassified from AOCI to earnings, Income Taxes | 1 | 0 |
Amounts reclassified from AOCI to earnings, Net of Income Taxes | (2) | 0 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Pretax | 600 | (10) |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Income Taxes | (153) | 3 |
Other comprehensive income, net of tax | 447 | (7) |
Unrealized loss on securities available for sale transferred to held to maturity |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, Net of Income Taxes | 0 | 0 |
Amounts reclassified from AOCI to earnings, Pretax | 1 | 1 |
Amounts reclassified from AOCI to earnings, Income Taxes | (1) | 0 |
Amounts reclassified from AOCI to earnings, Net of Income Taxes | 0 | 1 |
Other comprehensive income, net of tax | 0 | 1 |
Defined benefit pension items |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, Net of Income Taxes | 75 | 44 |
Amounts reclassified from AOCI to earnings, Net of Income Taxes | 0 | 0 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Pretax | 100 | 60 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Income Taxes | (25) | (16) |
Other comprehensive income, net of tax | 75 | 44 |
Unrealized gain on cash flow hedge derivatives |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, Pretax | 12 | 11 |
AOCI activity before reclassification, Income Taxes | (3) | (3) |
AOCI activity before reclassification, Net of Income Taxes | 9 | 8 |
Amounts reclassified from AOCI to earnings, Pretax | (4) | 0 |
Amounts reclassified from AOCI to earnings, Income Taxes | 1 | 0 |
Amounts reclassified from AOCI to earnings, Net of Income Taxes | (3) | 0 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Pretax | 8 | 11 |
Other comprehensive income (loss) on securities available for sale and cash flow hedges, Income Taxes | (2) | (3) |
Other comprehensive income, net of tax | $ 6 | $ 8 |

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