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Debt Securities (Schedule Of Amortized Cost, Gross Unrealized Gains And Losses, And Estimated Fair Value Of Securities Available For Sale And Securities Held To Maturity) (Details) - USD ($) $ in Millions | Sep. 30, 2025 | Dec. 31, 2024
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Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | $ 27,650 | $ 28,183
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 234 | 26
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (998) | (1,985)
Available-for-sale debt securities, net carrying value | 26,886 | 26,224
Debt securities available for sale | 26,886 | 26,224
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities held to maturity, amortized cost | 6,661 | 5,170
Held To Maturity Debt Securities Gross Unrealized Gains | 0 | 0
Held To Maturity Debt Securities Gross Unrealized Losses | (892) | (743)
Debt Securities held to maturity | 5,769 | 4,427
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Gain | 18 | 0
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Loss | (71) | (201)
Debt Securities held to maturity, estimated fair value | 5,716 | 4,226
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 2,316 | 2,088
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 9 | 2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (59) | (87)
Available-for-sale debt securities, net carrying value | 2,266 | 2,003
Debt securities available for sale | 2,266 | 2,003
Federal agency securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 614 | 460
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 5 | 1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (9) | (17)
Available-for-sale debt securities, net carrying value | 610 | 444
Debt securities available for sale | 610 | 444
Obligations of states and political subdivisions |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 2 | 2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 0 | 0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | 0 | 0
Available-for-sale debt securities, net carrying value | 2 | 2
Debt securities available for sale | 2 | 2
Residential agency |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 19,299 | 20,482
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 185 | 20
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (765) | (1,557)
Available-for-sale debt securities, net carrying value | 18,719 | 18,945
Debt securities available for sale | 18,719 | 18,945
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities held to maturity, amortized cost | 6,252 | 4,663
Held To Maturity Debt Securities Gross Unrealized Gains | 0 | 0
Held To Maturity Debt Securities Gross Unrealized Losses | (892) | (743)
Debt Securities held to maturity | 5,360 | 3,920
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Gain | 18 | 0
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Loss | (63) | (186)
Debt Securities held to maturity, estimated fair value | 5,315 | 3,734
Commercial agency |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 4,865 | 4,389
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 29 | 1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (152) | (300)
Available-for-sale debt securities, net carrying value | 4,742 | 4,090
Debt securities available for sale | 4,742 | 4,090
Schedule of Held-to-maturity Securities [Line Items] |  |
Debt Securities held to maturity, amortized cost | 409 | 507
Held To Maturity Debt Securities Gross Unrealized Gains | 0 | 0
Held To Maturity Debt Securities Gross Unrealized Losses | 0 | 0
Debt Securities held to maturity | 409 | 507
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Gain | 0 | 0
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Loss | (8) | (15)
Debt Securities held to maturity, estimated fair value | 401 | 492
Commercial non-agency |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 92 | 92
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 0 | 0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (9) | (10)
Available-for-sale debt securities, net carrying value | 83 | 82
Debt securities available for sale | 83 | 82
Corporate and other debt securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-sale, Amortized Cost | 462 | 670
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax | 6 | 2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax | (4) | (14)
Available-for-sale debt securities, net carrying value | 464 | 658
Debt securities available for sale | $ 464 | $ 658

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