Investments (Aggregate Fair Value And Gross Unrealized Loss By Length Of Time Security Has Continuously Been In Unrealized Loss Position) (Details) - Fixed Maturities [Member] - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 27,035	$ 57,189
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(974)	(4,115)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	56,471	14,991
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(7,062)	(2,291)
Debt Securities, Available-for-sale, Unrealized Loss Position	83,506	72,180
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(8,036)	(6,406)
U.S. Treasury / Agency
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,108	2,152
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(32)	(125)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,449	386
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(233)	(46)
Debt Securities, Available-for-sale, Unrealized Loss Position	3,557	2,538
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(265)	(171)
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	8,591	15,538
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(280)	(1,012)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	16,631	5,490
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(1,670)	(704)
Debt Securities, Available-for-sale, Unrealized Loss Position	25,222	21,028
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,950)	(1,716)
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	10,120	25,687
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(362)	(1,793)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	22,672	4,190
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(2,441)	(552)
Debt Securities, Available-for-sale, Unrealized Loss Position	32,792	29,877
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2,803)	(2,345)
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	5,827	10,561
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(249)	(1,033)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	13,450	4,770
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(2,510)	(941)
Debt Securities, Available-for-sale, Unrealized Loss Position	19,277	15,331
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2,759)	(1,974)
Municipal
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,389	3,251
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(51)	(152)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,269	155
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(208)	(48)
Debt Securities, Available-for-sale, Unrealized Loss Position	2,658	3,406
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (259)	$ (200)

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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