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Stockholders' Equity and Accumulated Other Comprehensive Income (Loss)(Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2024 | Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | $ (3,773) | $ (4,481)
Other Comprehensive Income (Loss), before Tax | (552) | 669
Pre-tax AOCI activity, Period End | (4,325) | (3,812)
Tax Effect, period start | 961 | 1,138
Unrealized holding gains (losses) arising during the period on securities available for sale, Tax | 81 | (114)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax | 13 | 0
Other Comprehensive Income (Loss), Tax | 140 | (170)
Tax Effect, period end | 1,101 | 968
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (2,812) | (3,343)
Unrealized holding gains (losses) arising during the period on securities available for sale, net of tax | (237) | 333
Reclassification adjustments for securities gains (losses) realized in net income (net of tax) | (37) | (2)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax | (303) | 148
Net change in unrealized gains (losses) on derivative instruments, net of tax | (216) | 159
Other comprehensive income (loss), net of tax | (412) | 499
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (3,224) | (2,844)
Accumulated Net Unrealized Loss on Held To Maturity Securities [Member] |  |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | (9) | (11)
Other Comprehensive Loss, Held-to-maturity Security, Reclassification Adjustment from AOCI for Noncredit Portion of OTTI, before Tax | 0 | 0
Pre-tax AOCI activity, Period End | (9) | (11)
Tax Effect, period start | 1 | 2
Reclassification adjustments for Amortization of Unrealized Losses on Securities Transferred to Held to Maturity, Tax | 0 | 0
Tax Effect, period end | 1 | 2
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (8) | (9)
Reclassification adjustments for Amortization of Unrealized Losses on Securities Transferred to Held to Maturity (net of tax) | 0 | 0
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (8) | (9)
Accumulated Net Unrealized Securities Available For Sale Gain (Loss) [Member] |  |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | (2,759) | (3,433)
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax | (318) | 447
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax | 50 | 2
Other Comprehensive Income (Loss), before Tax | (268) | 449
Pre-tax AOCI activity, Period End | (3,027) | (2,984)
Tax Effect, period start | 703 | 872
Unrealized holding gains (losses) arising during the period on securities available for sale, Tax | 81 | (114)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax | (13) | 0
Other Comprehensive Income (Loss), Tax | 68 | (114)
Tax Effect, period end | 771 | 758
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (2,056) | (2,561)
Reclassification adjustments for securities gains (losses) realized in net income (net of tax) | 37 | 2
Other comprehensive income (loss), net of tax | (200) | 335
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (2,256) | (2,226)
Accumulated Net Gain (Loss) from Derivative Instruments Designated as Cash Flow Hedges [Member] |  |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | (399) | (468)
OCI, before Reclassifications, before Tax, Attributable to Parent | (407) | 198
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent | (117) | (15)
Other Comprehensive Income (Loss), before Tax | (290) | 213
Pre-tax AOCI activity, Period End | (689) | (255)
Tax Effect, period start | 102 | 119
OCI, before reclassifications, tax, attributable to parent | 104 | (50)
Reclassification from AOCI, Current Period, Tax | (30) | (4)
Other Comprehensive Income (Loss), Tax | 74 | (54)
Tax Effect, period end | 176 | 65
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (297) | (349)
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent | 87 | 11
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (513) | (190)
Accumulated Defined Benefit Pension Plans Adjustment [Member] |  |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | (606) | (569)
Reclassification adjustments for amortization of actuarial (gains) losses and settlements realized in net income, before Tax | 6 | 7
Pre-tax AOCI activity, Period End | (600) | (562)
Tax Effect, period start | 155 | 145
Reclassification adjustments for amortization of actuarial (gains) losses and settlements realized in net income, Tax | (2) | (2)
Tax Effect, period end | 153 | 143
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (451) | (424)
Reclassification adjustments for amortization of actuarial (gains) losses and settlements realized in net income (net of tax) | 4 | 5
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | $ (447) | $ (419)

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