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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, 2023 | Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | $ (4,481) | $ 387
Other Comprehensive Income (Loss), before Tax | 669 | (2,016)
Pre-tax AOCI activity, Period End | (3,812) | (1,629)
Tax Effect, period start | 1,138 | (98)
Unrealized holding gains (losses) arising during the period on securities available for sale, Tax | (114) | 381
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax | 0 | 0
Other Comprehensive Income (Loss), Tax | (170) | 513
Tax Effect, period end | 968 | 415
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (3,343) | 289
Unrealized holding gains (losses) arising during the period on securities available for sale, net of tax | 333 | (1,117)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax | 148 | (311)
Reclassification adjustments for securities gains (losses) realized in net income (net of tax) | (2) | 0
Net change in unrealized gains (losses) on derivative instruments, net of tax | 159 | (393)
Other comprehensive income (loss), net of tax | 499 | (1,503)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (2,844) | (1,214)
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 | (11) | (14)
Other Comprehensive Loss, Held-to-maturity Security, Reclassification Adjustment from AOCI for Noncredit Portion of OTTI, before Tax | 0 | 1
Pre-tax AOCI activity, Period End | (11) | (13)
Tax Effect, period start | 2 | 3
Reclassification adjustments for Amortization of Unrealized Losses on Securities Transferred to Held to Maturity, Tax | 0 | 0
Tax Effect, period end | 2 | 3
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (9) | (11)
Reclassification adjustments for Amortization of Unrealized Losses on Securities Transferred to Held to Maturity (net of tax) | 0 | 1
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (9) | (10)
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 | (3,433) | 218
OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax | 447 | (1,498)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax | 2 |
Other Comprehensive Income (Loss), before Tax | 449 |
Pre-tax AOCI activity, Period End | (2,984) | (1,280)
Tax Effect, period start | 872 | (55)
Unrealized holding gains (losses) arising during the period on securities available for sale, Tax | (114) | (381)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax | 0 |
Other Comprehensive Income (Loss), Tax | (114) |
Tax Effect, period end | 758 | 326
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (2,561) | 163
Reclassification adjustments for securities gains (losses) realized in net income (net of tax) | 2 |
Other comprehensive income (loss), net of tax | 335 |
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (2,226) | (954)
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 | (468) | 830
OCI, before Reclassifications, before Tax, Attributable to Parent | 198 | (417)
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent | (15) | 110
Other Comprehensive Income (Loss), before Tax | 213 | (527)
Pre-tax AOCI activity, Period End | (255) | 303
Tax Effect, period start | 119 | (209)
OCI, before reclassifications, tax, attributable to parent | (50) | 106
Reclassification from AOCI, Current Period, Tax | (4) | 28
Other Comprehensive Income (Loss), Tax | (54) | 134
Tax Effect, period end | 65 | (75)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (349) | 621
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent | 11 | 82
Other comprehensive income (loss), net of tax |  | (393)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (190) | 228
Accumulated Defined Benefit Pension Plans Adjustment [Member] |  |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] |  |
Pre-tax AOCI activity, Period Start | (569) | (647)
Reclassification adjustments for amortization of actuarial (gains) losses and settlements realized in net income, before Tax | 7 | 8
Pre-tax AOCI activity, Period End | (562) | (639)
Tax Effect, period start | 145 | 163
Reclassification adjustments for amortization of actuarial (gains) losses and settlements realized in net income, Tax | (2) | (2)
Tax Effect, period end | 143 | 161
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (424) | (484)
Reclassification adjustments for amortization of actuarial (gains) losses and settlements realized in net income (net of tax) | 5 | 6
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | $ (419) | $ (478)

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