Investments (Aggregate Fair Value And Gross Unrealized Loss By Length Of Time Security Has Continuously Been In Unrealized Loss Position) (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 75,565	$ 12,574
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(3,251)	(237)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	26,480	32,375
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(4,375)	(2,899)
Debt Securities, Available-for-sale, Unrealized Loss Position	102,045	44,949
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(7,626)	(3,136)
U.S. and local government securities
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,404	307
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(73)	(3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,764	2,139
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(320)	(216)
Debt Securities, Available-for-sale, Unrealized Loss Position	3,168	2,446
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(393)	(219)
Non-U.S.
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	22,099	6,664
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(944)	(163)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	8,207	8,995
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(968)	(622)
Debt Securities, Available-for-sale, Unrealized Loss Position	30,306	15,659
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,912)	(785)
Corporate and asset-backed securities
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	28,769	4,136
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,130)	(59)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	7,905	10,225
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,354)	(867)
Debt Securities, Available-for-sale, Unrealized Loss Position	36,674	14,361
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2,484)	(926)
Mortgage-backed securities
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	23,293	1,467
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,104)	(12)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	8,604	11,016
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,733)	(1,194)
Debt Securities, Available-for-sale, Unrealized Loss Position	31,897	12,483
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (2,837)	$ (1,206)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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