Derivative Instruments (Non Hedging Derivatives and Embedded Derivatives Effect on Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	$ (85)	$ 13	$ (331)	$ (110)
Interest credited	(533)	(547)	(1,630)	(1,160)
Not Designated as Hedging Instrument
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	95	(100)	118	(28)
Gain Loss On Investments Related To Change In Fair Value Of Derivatives Excluding Embedded Derivatives	(29)	32	2	80
Not Designated as Hedging Instrument \| Interest Rate Swaps
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	4	1	8	6
Not Designated as Hedging Instrument \| Financial Futures
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	1	(13)	(18)	(25)
Not Designated as Hedging Instrument \| Currency Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(2)	6	5	1
Not Designated as Hedging Instrument \| Foreign Currency Forwards
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	15	(40)	(48)	22
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	3	9	(3)
Not Designated as Hedging Instrument \| Equity Options
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	14	30	68	35
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	104	(33)	145	(41)
Not Designated as Hedging Instrument \| Embedded Derivatives In Indexed Annuity [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	20	(99)	(29)	(67)
Not Designated as Hedging Instrument \| Total Return Swap
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(36)	16	(39)	16
Not Designated as Hedging Instrument \| Interest Rate Swaption
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(1)	(2)	(1)	(3)
Not Designated as Hedging Instrument \| Credit Default Swaps
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(28)	33	24	36
Not Designated as Hedging Instrument \| Foreign Exchange Option
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	0	(2)	(3)	(5)
Not Designated as Hedging Instrument \| Credit Default Option
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	$ (1)	$ 0	$ (3)	$ 0