Debt Securities (Schedule Of Gross Unrealized Losses And Estimated Fair Value Of Securities Available For Sale) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 6,419	$ 9,881
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(148)	(256)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	11,663	14,303
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,046)	(1,729)
Debt Securities, Available-for-sale, Unrealized Loss Position	18,082	24,184
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,194)	(1,985)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Estimated Fair Value	199	0
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(3)	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Estimated Fair Value	5,612	4,226
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,060)	(944)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	5,811	4,226
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss	(1,063)	(944)
U.S. Treasury securities
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	517	612
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(19)	(14)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,030	1,033
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(51)	(73)
Debt Securities, Available-for-sale, Unrealized Loss Position	1,547	1,645
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(70)	(87)
Federal agency securities
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	75	155
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)	(3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	184	195
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(9)	(14)
Debt Securities, Available-for-sale, Unrealized Loss Position	259	350
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(10)	(17)
Residential agency
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	5,021	8,012
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(102)	(203)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	7,485	9,605
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(805)	(1,354)
Debt Securities, Available-for-sale, Unrealized Loss Position	12,506	17,617
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(907)	(1,557)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Estimated Fair Value	199	0
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(3)	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Estimated Fair Value	5,165	3,734
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,049)	(929)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	5,364	3,734
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss	(1,052)	(929)
Commercial agency
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	801	1,043
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(26)	(35)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,625	2,991
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(165)	(265)
Debt Securities, Available-for-sale, Unrealized Loss Position	3,426	4,034
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(191)	(300)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Estimated Fair Value	0	0
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Estimated Fair Value	447	492
Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(11)	(15)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	447	492
Debt Securities, Held-to-Maturity, Unrealized Loss Position, Accumulated Loss	(11)	(15)
Commercial non-agency
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	83	82
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(9)	(10)
Debt Securities, Available-for-sale, Unrealized Loss Position	83	82
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(9)	(10)
Corporate and other debt securities
Unrealized Loss And Fair Value On Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	5	59
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	256	397
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(7)	(13)
Debt Securities, Available-for-sale, Unrealized Loss Position	261	456
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (7)	$ (14)

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

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