Derivative Instruments (Gross Notional Amount and Fair Value of Derivatives Contracts) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Notional Amount of Derivatives	$ 23,516	$ 23,298
Derivative Asset, Fair Value, Gross Asset	421	229
Derivative Liability, Fair Value, Gross Liability	975	987
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount of Derivatives	20,557	21,007
Derivative Asset, Fair Value, Gross Asset	388	208
Derivative Liability, Fair Value, Gross Liability	930	947
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,273	1,084
Derivative Asset, Fair Value, Gross Asset	66	93
Derivative Liability, Fair Value, Gross Liability	1	1
Not Designated as Hedging Instrument [Member] | Future [Member]
Derivative [Line Items]
Notional Amount of Derivatives	240	258
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative [Line Items]
Notional Amount of Derivatives	395	347
Derivative Asset, Fair Value, Gross Asset	2	4
Derivative Liability, Fair Value, Gross Liability	4	2
Not Designated as Hedging Instrument [Member] | Consumer Price Index Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	563	612
Derivative Asset, Fair Value, Gross Asset	34	11
Derivative Liability, Fair Value, Gross Liability	7	19
Not Designated as Hedging Instrument [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,321	1,517
Derivative Asset, Fair Value, Gross Asset	29	13
Derivative Liability, Fair Value, Gross Liability	1	0
Not Designated as Hedging Instrument [Member] | Equity [Member]
Derivative [Line Items]
Notional Amount of Derivatives	472	395
Derivative Asset, Fair Value, Gross Asset	29	29
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument [Member] | Longevity Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	16,143
Not Designated as Hedging Instrument [Member] | Synthetic Guaranteed Investment Contracts [Member]
Derivative [Line Items]
Notional Amount of Derivatives	16,143	16,644
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument [Member] | Embedded Derivatives In Modified Coinsurance Or Funds Withheld Arrangements [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	0
Derivative Asset, Fair Value, Gross Asset	227	58
Derivative Liability, Fair Value, Gross Liability	62	0
Not Designated as Hedging Instrument [Member] | Embedded Derivatives In Indexed Annuity [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	693	752
Not Designated as Hedging Instrument [Member] | Embedded Derivatives In Variable Annuity [Member]
Derivative [Line Items]
Notional Amount of Derivatives	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	162	155
Not Designated as Hedging Instrument [Member] | Currency Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	150	150
Derivative Asset, Fair Value, Gross Asset	1	0
Derivative Liability, Fair Value, Gross Liability	0	18
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Notional Amount of Derivatives	2,959	2,291
Derivative Asset, Fair Value, Gross Asset	33	21
Derivative Liability, Fair Value, Gross Liability	45	40
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	941	802
Derivative Asset, Fair Value, Gross Asset	4	3
Derivative Liability, Fair Value, Gross Liability	33	24
Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative [Line Items]
Notional Amount of Derivatives	1,320	1,255
Derivative Asset, Fair Value, Gross Asset	14	10
Derivative Liability, Fair Value, Gross Liability	11	15
Designated as Hedging Instrument [Member] | Currency Swap [Member]
Derivative [Line Items]
Notional Amount of Derivatives	153	234
Derivative Asset, Fair Value, Gross Asset	1	8
Derivative Liability, Fair Value, Gross Liability	0	1
Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Derivative [Line Items]
Notional Amount of Derivatives	545	0
Derivative Asset, Fair Value, Gross Asset	14	0
Derivative Liability, Fair Value, Gross Liability	$ 1	$ 0