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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, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, net of income taxes | $ (755) | $ 4 |
Reclassification from AOCI, net of income taxes | 10 | (6) |
Other comprehensive (loss) income, pretax | (980) | (3) |
Other comprehensive (loss) income, income taxes | 235 | 1 |
Other comprehensive (loss) income, net of tax | (745) | (2) | $ 139
Defined benefit pension items |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, pretax | (33) | 98 |
AOCI activity before reclassification, income taxes | 8 | (22) |
AOCI activity before reclassification, net of income taxes | (25) | 76 |
Reclassification from AOCI, net of income taxes | 9 | 21 |
Other comprehensive (loss) income, pretax | (21) | 125 |
Other comprehensive (loss) income, income taxes | 5 | (28) |
Other comprehensive (loss) income, net of tax | (16) | 97 |
Defined benefit pension items | Other noninterest expense |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
Reclassification from AOCI, pretax | 12 | 27 |
Reclassification from AOCI, income taxes | (3) | (6) |
Reclassification from AOCI, net of income taxes | 9 | 21 |
Unrealized loss on securities available for sale transferred to securities held to maturity |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, pretax | 0 | (13) |
AOCI activity before reclassification, income taxes | 0 | 3 |
AOCI activity before reclassification, net of income taxes | 0 | (10) |
Reclassification from AOCI, net of income taxes | 1 | (1) |
Other comprehensive (loss) income, pretax | 1 | (14) |
Other comprehensive (loss) income, income taxes | 0 | 3 |
Other comprehensive (loss) income, net of tax | 1 | (11) |
Unrealized loss on securities available for sale transferred to securities held to maturity | Interest on investment securities |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
Reclassification from AOCI, pretax | 1 | (1) |
Reclassification from AOCI, income taxes | 0 | 0 |
Reclassification from AOCI, net of income taxes | 1 | (1) |
Unrealized (loss) gain on securities available for sale |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
AOCI activity before reclassification, pretax | (960) | (81) |
AOCI activity before reclassification, income taxes | 230 | 19 |
AOCI activity before reclassification, net of income taxes | (730) | (62) |
Reclassification from AOCI, net of income taxes | 0 | (26) |
Other comprehensive (loss) income, pretax | (960) | (114) |
Other comprehensive (loss) income, income taxes | 230 | 26 |
Other comprehensive (loss) income, net of tax | (730) | (88) |
Unrealized (loss) gain on securities available for sale | Realized gain on sale of investment securities available for sale, net |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |
Reclassification from AOCI, pretax | 0 | (33) |
Reclassification from AOCI, income taxes | 0 | 7 |
Reclassification from AOCI, net of income taxes | $ 0 | $ (26) |

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