Securities (Schedule Of Gross Unrealized Losses And Estimated Fair Value Of Securities Available For Sale and Held to Maturity) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Unrealized Loss And Fair Value On Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Estimated Fair Value	$ 817
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(31)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Estimated Fair Value	0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	817
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	31
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	22,224	$ 12,378
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,459	216
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	5,461	1,446
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	799	59
Debt Securities, Available-for-sale, Unrealized Loss Position	27,685	13,824
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	2,258	275
US Treasury Securities [Member]
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	994	1,010
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	82	7
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	5	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1	0
Debt Securities, Available-for-sale, Unrealized Loss Position	999	1,010
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	83	7
Federal Agency Securities [Member]
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	623	63
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	19	3
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	56	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	9	0
Debt Securities, Available-for-sale, Unrealized Loss Position	679	63
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	28	3
Residential Agency [Member]
Unrealized Loss And Fair Value On Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Estimated Fair Value	296
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(20)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Estimated Fair Value	0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	296
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	20
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	14,107	9,528
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1,077	171
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	4,321	686
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	654	27
Debt Securities, Available-for-sale, Unrealized Loss Position	18,428	10,214
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	1,731	198
Commercial Agency [Member]
Unrealized Loss And Fair Value On Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Estimated Fair Value	521
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(11)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Estimated Fair Value	0
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	521
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	11
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	5,214	1,333
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	225	29
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,003	760
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	131	32
Debt Securities, Available-for-sale, Unrealized Loss Position	6,217	2,093
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	356	61
Commercial Non-Agency [Member]
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	315
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	315
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	9
Corporate and other debt securities [Member]
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	971	444
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	47	6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	76	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	4	0
Debt Securities, Available-for-sale, Unrealized Loss Position	1,047	444
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 51	$ 6

Unrealized Loss And Fair Value Available For Sale Securities [Line Items]

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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