Derivative Instruments (Gross Notional Amount and Fair Value of Derivatives Contracts) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Notional Amount	$ 33,903	$ 32,104
Carrying Value / Fair Value of Assets	440	510
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	1,156	1,196
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional Amount	29,116	27,306
Carrying Value / Fair Value of Assets	416	478
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	862	949
Not Designated as Hedging Instrument | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	1,400	1,609
Carrying Value / Fair Value of Assets	5	4
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	11	3
Not Designated as Hedging Instrument | Foreign Currency Forwards
Derivative [Line Items]
Notional Amount	2,489	809
Carrying Value / Fair Value of Assets	0	36
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	27	0
Not Designated as Hedging Instrument | Financial Futures
Derivative [Line Items]
Notional Amount	211	255
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	0	0
Not Designated as Hedging Instrument | Consumer Price Index Swap [Member]
Derivative [Line Items]
Notional Amount	456	468
Carrying Value / Fair Value of Assets	11	11
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	2	3
Not Designated as Hedging Instrument | Credit Default Swaps
Derivative [Line Items]
Notional Amount	2,005	1,475
Carrying Value / Fair Value of Assets	4	5
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	3	1
Not Designated as Hedging Instrument | Synthetic Guaranteed Investment Contracts
Derivative [Line Items]
Notional Amount	15,801	16,135
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	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	327	356
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	421	527
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, Subject to Master Netting Arrangement, before Offset of Collateral	398	415
Not Designated as Hedging Instrument | Currency Swap [Member]
Derivative [Line Items]
Notional Amount	150	150
Carrying Value / Fair Value of Assets	39	27
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	0	0
Not Designated as Hedging Instrument | Interest Rate Swaption
Derivative [Line Items]
Notional Amount	5,555	5,555
Carrying Value / Fair Value of Assets	3	7
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	0	0
Not Designated as Hedging Instrument | Total Return Swap
Derivative [Line Items]
Notional Amount	700	500
Carrying Value / Fair Value of Assets	23	24
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	0	0
Not Designated as Hedging Instrument | Interest Rate Future
Derivative [Line Items]
Notional Amount	96	97
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	0	0
Not Designated as Hedging Instrument | Equity Option
Derivative [Line Items]
Notional Amount	253	253
Carrying Value / Fair Value of Assets	4	8
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	0	0
Designated As Hedging Instrument
Derivative [Line Items]
Notional Amount	4,787	4,798
Carrying Value / Fair Value of Assets	24	32
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	294	247
Designated As Hedging Instrument | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	1,830	1,770
Carrying Value / Fair Value of Assets	1	9
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	97	86
Designated As Hedging Instrument | Foreign Currency Forwards
Derivative [Line Items]
Notional Amount	1,143	1,143
Carrying Value / Fair Value of Assets	15	5
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	2	17
Designated As Hedging Instrument | Currency Swap [Member]
Derivative [Line Items]
Notional Amount	742	809
Carrying Value / Fair Value of Assets	6	7
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	88	64
Designated As Hedging Instrument | Forward Contracts [Member]
Derivative [Line Items]
Notional Amount	1,072	1,076
Carrying Value / Fair Value of Assets	2	11
Derivative Liability, Subject to Master Netting Arrangement, before Offset of Collateral	$ 107	$ 80