Derivative Instruments (Gross Notional Amount and Fair Value of Derivatives Contracts) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Notional Amount	$ 40,426	$ 35,830
Carrying Value / Fair Value of Assets	191	187
Derivative Liability, Fair Value, Gross Liability	548	550
Derivative Asset, Subject to Master Netting Arrangement, after Offset	501	470
Derivative Liability, Subject to Master Netting Arrangement, after Offset	1,275	1,323
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional Amount	30,578	26,500
Carrying Value / Fair Value of Assets	442	364
Derivative Liability, Fair Value, Gross Liability	815	855
Not Designated as Hedging Instrument | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	1,907	1,848
Carrying Value / Fair Value of Assets	8	6
Derivative Liability, Fair Value, Gross Liability	13	20
Not Designated as Hedging Instrument | Foreign Currency Forwards
Derivative [Line Items]
Notional Amount	1,261	1,148
Derivative Asset, Subject to Master Netting Arrangement, after Offset	23	9
Derivative Liability, Subject to Master Netting Arrangement, after Offset	3	37
Not Designated as Hedging Instrument | Financial Futures
Derivative [Line Items]
Notional Amount	224	209
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Consumer Price Index Swap [Member]
Derivative [Line Items]
Notional Amount	415	408
Carrying Value / Fair Value of Assets	2	6
Derivative Liability, Fair Value, Gross Liability	8	2
Not Designated as Hedging Instrument | Synthetic Guaranteed Investment Contracts
Derivative [Line Items]
Notional Amount	16,769	15,362
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Embedded Derivatives In Modified Coinsurance Or Funds Withheld Arrangements
Derivative [Line Items]
Notional Amount	0	0
Carrying Value / Fair Value of Assets	310	283
Derivative Liability, Fair Value, Gross Liability	373	338
Not Designated as Hedging Instrument | Embedded Derivatives In Indexed Annuity [Member]
Derivative [Line Items]
Notional Amount	0	0
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	354	435
Not Designated as Hedging Instrument | Currency Swap [Member]
Derivative [Line Items]
Notional Amount	150	150
Derivative Asset, Subject to Master Netting Arrangement, after Offset	39	47
Derivative Liability, Subject to Master Netting Arrangement, after Offset	0	0
Not Designated as Hedging Instrument | Interest Rate Swaption
Derivative [Line Items]
Notional Amount	500	1,773
Carrying Value / Fair Value of Assets	1	1
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Total Return Swap
Derivative [Line Items]
Notional Amount	735	956
Carrying Value / Fair Value of Assets	2	0
Derivative Liability, Fair Value, Gross Liability	14	14
Not Designated as Hedging Instrument | Foreign Exchange Option
Derivative [Line Items]
Notional Amount	430	430
Derivative Asset, Subject to Master Netting Arrangement, after Offset	2	1
Derivative Liability, Subject to Master Netting Arrangement, after Offset	0	0
Not Designated as Hedging Instrument | Equity Option
Derivative [Line Items]
Notional Amount	956	255
Carrying Value / Fair Value of Assets	48	5
Derivative Liability, Fair Value, Gross Liability	18	1
Not Designated as Hedging Instrument | Credit Default Swaps
Derivative [Line Items]
Notional Amount	5,288	2,661
Carrying Value / Fair Value of Assets	5	4
Derivative Liability, Fair Value, Gross Liability	30	6
Not Designated as Hedging Instrument | Credit Default Option
Derivative [Line Items]
Notional Amount	100	0
Derivative Asset, Subject to Master Netting Arrangement, after Offset	0	0
Derivative Liability, Subject to Master Netting Arrangement, after Offset	0	0
Not Designated as Hedging Instrument | Swap
Derivative [Line Items]
Notional Amount	1,843	1,300
Carrying Value / Fair Value of Assets	2	2
Derivative Liability, Fair Value, Gross Liability	2	2
Designated As Hedging Instrument
Derivative [Line Items]
Notional Amount	9,848	9,330
Derivative Asset, Subject to Master Netting Arrangement, after Offset	59	106
Derivative Liability, Subject to Master Netting Arrangement, after Offset	460	468
Designated As Hedging Instrument | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	3,223	3,336
Derivative Asset, Subject to Master Netting Arrangement, after Offset	38	5
Derivative Liability, Subject to Master Netting Arrangement, after Offset	68	103
Designated As Hedging Instrument | Foreign Currency Forwards
Derivative [Line Items]
Notional Amount	2,259	1,966
Derivative Asset, Subject to Master Netting Arrangement, after Offset	2	94
Derivative Liability, Subject to Master Netting Arrangement, after Offset	75	0
Designated As Hedging Instrument | Currency Swap [Member]
Derivative [Line Items]
Notional Amount	2,008	2,008
Derivative Asset, Subject to Master Netting Arrangement, after Offset	14	7
Derivative Liability, Subject to Master Netting Arrangement, after Offset	91	159
Designated As Hedging Instrument | Forward Contracts [Member]
Derivative [Line Items]
Notional Amount	2,358	2,020
Derivative Asset, Subject to Master Netting Arrangement, after Offset	5	0
Derivative Liability, Subject to Master Netting Arrangement, after Offset	$ 226	$ 206