Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And Other Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Gain (Loss) on Securities [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)		$ (214)	$ (237)
Foreign exchange gains( losses)		(183)	397	$ 340
Derivative, Gain (Loss) on Derivative, Net		(252)	133
Net realized gains (losses)		(607)	(1,085)	1,030
Unrealized Gain (Loss) on Investments		3,120	(9,535)	(2,417)
Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax		(328)	1,043	521
Other derivative instruments
Gain (Loss) on Securities [Line Items]
Derivative, Gain (Loss) on Derivative, Net		(10)	(11)	(8)
Investment and embedded derivative instruments
Gain (Loss) on Securities [Line Items]
Derivative, Gain (Loss) on Derivative, Net		(53)	(43)	(72)
Fixed Maturities [Member]
Gain (Loss) on Securities [Line Items]
Debt Securities, Available-for-sale, Realized Gain (Loss), Excluding Other-than-temporary Impairment		208	619	142
Debt Securities, Available-for-sale, Realized Loss, Excluding Other-than-temporary Impairment		(656)	(1,379)	(123)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)		43	154	14
Debt Securities, Available-For-Sale, Credit Impairment Charges Intent to Sell	[1]	(64)	(135)	(30)
Debt Securities, Available-for-sale, Realized Gain (Loss)		(481)	(1,049)	3
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Equity Securities, FV-NI, Realized Gain (Loss)		(38)	(230)	662
Unrealized Gain (Loss) on Investments		30	(639)	505
Other Investments
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)		(12)	0	0
Unrealized Gain (Loss) on Investments		(12)
Available-for-sale Securities [Member]
Gain (Loss) on Securities [Line Items]
Unrealized Gain (Loss) on Investments		3,563	(10,583)	(2,901)
Fixed maturities held to maturity
Gain (Loss) on Securities [Line Items]
Unrealized Gain (Loss) on Investments		(125)	(15)	(18)
Other [Member]
Gain (Loss) on Securities [Line Items]
Gain (Loss) on Sale of Other Investments		88	(118)	(6)
Unrealized Gain (Loss) on Investments		10	20	(19)
Equity securities and other investments [Member]
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)		20	(261)	773
Unrealized Gain (Loss) on Investments		88	(670)	616
Private equities
Gain (Loss) on Securities [Line Items]
Net realized gains (losses)		70	(31)	111
Unrealized Gain (Loss) on Investments		$ 70	$ (31)	$ 111

[1] Relates to certain securities we intended to sell and securities written to market entering default.