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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	Dec. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 28,183	$ 30,864
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	26	62
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(1,985)	(2,822)
Available-for-sale debt securities, net carrying value	26,224	28,104
Debt securities available for sale	26,224	28,104
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities held to maturity, amortized cost	5,170	763
Held To Maturity Debt Securities Gross Unrealized Gains	0	0
Held To Maturity Debt Securities Gross Unrealized Losses	(743)	(9)
Debt Securities held to maturity	4,427	754
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Loss	(201)	(38)
Debt Securities held to maturity, estimated fair value	4,226	716
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	2,088	1,322
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(87)	(99)
Available-for-sale debt securities, net carrying value	2,003	1,223
Debt securities available for sale	2,003	1,223
Federal agency securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	460	1,085
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1	4
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(17)	(46)
Available-for-sale debt securities, net carrying value	444	1,043
Debt securities available for sale	444	1,043
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	20,482	19,450
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	20	52
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(1,557)	(2,130)
Available-for-sale debt securities, net carrying value	18,945	17,372
Debt securities available for sale	18,945	17,372
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities held to maturity, amortized cost	4,663	247
Held To Maturity Debt Securities Gross Unrealized Gains	0	0
Held To Maturity Debt Securities Gross Unrealized Losses	(743)	(8)
Debt Securities held to maturity	3,920	239
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Loss	(186)	(16)
Debt Securities held to maturity, estimated fair value	3,734	223
Commercial agency
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	4,389	7,807
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1	2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(300)	(502)
Available-for-sale debt securities, net carrying value	4,090	7,307
Debt securities available for sale	4,090	7,307
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities held to maturity, amortized cost	507	516
Held To Maturity Debt Securities Gross Unrealized Gains	0	0
Held To Maturity Debt Securities Gross Unrealized Losses	0	(1)
Debt Securities held to maturity	507	515
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Gain	0	0
Held-to-maturity Debt Securities, Accumulated Unrecognized Holding Loss	(15)	(22)
Debt Securities held to maturity, estimated fair value	492	493
Commercial non-agency
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	92	93
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(10)	(10)
Available-for-sale debt securities, net carrying value	82	83
Debt securities available for sale	82	83
Corporate and other debt securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	670	1,105
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2	4
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(14)	(35)
Available-for-sale debt securities, net carrying value	658	1,074
Debt securities available for sale	$ 658	$ 1,074

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