Investments (Aggregate Fair Value And Gross Unrealized Loss By Length Of Time Security Has Continuously Been In Unrealized Loss Position) (Details) - USD ($) $ in Millions	Jun. 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	$ 34,436	$ 12,574
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(629)	(237)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	28,152	32,375
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(3,046)	(2,899)
Debt Securities, Available-for-sale, Unrealized Loss Position	62,588	44,949
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(3,675)	(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	928	307
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(14)	(3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,891	2,139
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(227)	(216)
Debt Securities, Available-for-sale, Unrealized Loss Position	2,819	2,446
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(241)	(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	12,200	6,664
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(344)	(163)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	8,121	8,995
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(693)	(622)
Debt Securities, Available-for-sale, Unrealized Loss Position	20,321	15,659
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,037)	(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	13,317	4,136
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(182)	(59)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	8,502	10,225
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(875)	(867)
Debt Securities, Available-for-sale, Unrealized Loss Position	21,819	14,361
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,057)	(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	7,991	1,467
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(89)	(12)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	9,638	11,016
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,251)	(1,194)
Debt Securities, Available-for-sale, Unrealized Loss Position	17,629	12,483
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (1,340)	$ (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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