Derivative Instruments (Non Hedging Derivatives and Embedded Derivatives Effect on Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	$ (79)	$ (149)
Gain Loss On Investments Related To Change In Fair Value Of Derivatives Excluding Embedded Derivatives	(2)	(98)
Interest credited	(299)	(254)
Not Designated as Hedging Instrument
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	11	(41)
Not Designated as Hedging Instrument | Interest Rate Swaps
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	6	(31)
Not Designated as Hedging Instrument | Financial Futures
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	9	(17)
Not Designated as Hedging Instrument | Currency Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(3)	14
Not Designated as Hedging Instrument | Foreign Currency Forwards
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	22	(64)
Not Designated as Hedging Instrument | Consumer Price Index Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(5)	0
Not Designated as Hedging Instrument | Credit Default Swaps
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(18)	2
Not Designated as Hedging Instrument | Equity Options
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(6)	(4)
Not Designated as Hedging Instrument | Embedded Derivatives In Modified Coinsurance Or Funds Withheld Arrangements
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(11)	77
Not Designated as Hedging Instrument | Embedded Derivatives In Indexed Annuity [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Interest credited	(24)	(20)
Not Designated as Hedging Instrument | Interest Rate Future
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	0	1
Not Designated as Hedging Instrument | Total Return Swap
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(6)	4
Not Designated as Hedging Instrument | Interest Rate Swaption
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	0	(3)
Not Designated as Hedging Instrument | Foreign Exchange Option
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	$ (1)	$ 0