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ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Schedule of Pretax and After-tax Components of Other Comprehensive Income (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
AOCI activity before reclassification, net amount |  |  |  | $ (50)
Amounts reclassified from AOCI to earnings, net amount |  |  |  | 13
Other comprehensive income (loss) on securities available for sale, gross amount | $ (37) | $ (139) | $ (161) | (51)
Other comprehensive loss on securities available for sale, tax | 9 | 36 | 42 | 14
Other comprehensive loss, net of tax | (28) | (103) | (119) | (37)
Realized loss on sale of investment securities available for sale, net | 0 | 0 | 0 | 14
Provision for credit losses | 0 | (1) | 0 | 3
Unrealized loss on securities available for sale: |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
AOCI activity before reclassification, gross amount | (30) | (134) | (154) | (74)
AOCI activity before reclassification, tax | 8 | 35 | 41 | 20
AOCI activity before reclassification, net amount | (22) | (99) | (113) | (54)
Amounts reclassified from AOCI to earnings, gross amount | 0 | (1) | 0 | 17
Amounts reclassified from AOCI to earnings, tax | 0 | 0 | 0 | (5)
Amounts reclassified from AOCI to earnings, net amount | 0 | (1) | 0 | 12
Other comprehensive income (loss) on securities available for sale, gross amount | (30) | (135) | (154) | (57)
Other comprehensive loss on securities available for sale, tax | 8 | 35 | 41 | 15
Other comprehensive loss, net of tax | (22) | (100) | (113) | (42)
Unrealized loss on securities available for sale transferred to held to maturity |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
AOCI activity before reclassification, net amount |  |  |  | 0
Amounts reclassified from AOCI to earnings, gross amount | 0 | 1 | 0 | 1
Amounts reclassified from AOCI to earnings, tax | 0 | 0 | 0 | 0
Amounts reclassified from AOCI to earnings, net amount | 0 | 1 | 0 | 1
Other comprehensive income (loss) on securities available for sale, gross amount | 0 | 1 | 0 | 1
Other comprehensive loss on securities available for sale, tax | 0 | 0 | 0 | 0
Other comprehensive loss, net of tax | 0 | 1 | 0 | 1
Defined benefit pension items |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
AOCI activity before reclassification, net amount |  |  |  | 4
Amounts reclassified from AOCI to earnings, net amount |  |  |  | 0
Other comprehensive income (loss) on securities available for sale, gross amount | (10) | (5) | (10) | 5
Other comprehensive loss on securities available for sale, tax | 2 | 1 | 2 | (1)
Other comprehensive loss, net of tax | (8) | (4) | (8) | 4
Unrealized gain on cash flow hedge derivatives |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
AOCI activity before reclassification, net amount |  |  |  | 0
Amounts reclassified from AOCI to earnings, net amount |  |  |  | 0
Other comprehensive income (loss) on securities available for sale, gross amount | 3 | 0 | 3 | 0
Other comprehensive loss on securities available for sale, tax | (1) | 0 | (1) | 0
Other comprehensive loss, net of tax | $ 2 | $ 0 | $ 2 | $ 0

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