Debt Securities (Schedule Of Fair Value And Unrealized Losses Of Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 3,423	$ 1,366
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(36)	(9)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,888	3,371
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(374)	(371)
Debt Securities, Available-for-sale, Unrealized Loss Position	6,311	4,737
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(410)	(380)
U.S. Treasury and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	100	50
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	775	778
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(39)	(38)
Debt Securities, Available-for-sale, Unrealized Loss Position	875	828
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(40)	(38)
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	434	29
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(4)	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	151	219
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(16)	(15)
Debt Securities, Available-for-sale, Unrealized Loss Position	585	248
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(20)	(15)
Mortgage-backed securities and collateralized mortgage obligations
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	2,889	1,287
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(31)	(9)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,962	2,374
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(319)	(318)
Debt Securities, Available-for-sale, Unrealized Loss Position	4,851	3,661
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (350)	$ (327)

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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