Derivative Instruments (Outstanding Derivative Instruments With Off-Balance-Sheet Risks) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	$ 207,746
Interest Rate Contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	135,581
Foreign currency contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	3,110
Equity market contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	69,001
Credit contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	54
Total Derivative Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	207,746	$ 163,315
Asset Fair Value	5,273	4,384
Liability Fair Value	6,415	4,306
Derivative Investments [Member] \| Interest Rate Contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	131,973	112,921
Asset Fair Value	1,752	1,082
Liability Fair Value	142	219
Derivative Investments [Member] \| Foreign currency contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	239	262
Asset Fair Value	3	1
Liability Fair Value		3
Derivative Investments [Member] \| Equity market contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	69,001	43,555
Asset Fair Value	2,211	1,442
Liability Fair Value	1,070	664
Derivative Investments [Member] \| Credit contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	54	55
Derivative Investments [Member] \| Cash Flow Hedges [Member] \| Designated as Hedging Instrument [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	5,318	5,261
Asset Fair Value	489	299
Liability Fair Value	762	296
Derivative Investments [Member] \| Cash Flow Hedges [Member] \| Interest Rate Contracts [Member] \| Designated as Hedging Instrument [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	2,447	2,387
Asset Fair Value	169	108
Liability Fair Value	726	245
Derivative Investments [Member] \| Cash Flow Hedges [Member] \| Foreign currency contracts [Member] \| Designated as Hedging Instrument [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	2,871	2,874
Asset Fair Value	320	191
Liability Fair Value	36	51
Derivative Investments [Member] \| Fair Value Hedges [Member] \| Interest Rate Contracts [Member] \| Designated as Hedging Instrument [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	1,161	1,261
Asset Fair Value	1	123
Liability Fair Value	313	203
Other Assets [Member] \| GLB Direct Embedded Derivatives [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Asset Fair Value		450
Liability Fair Value	1,106
Other Liabilities [Member] \| GLB Ceded Embedded Derivatives [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Asset Fair Value	281	60
Liability Fair Value		9
Reinsurance Related Embedded Derivatives [Member] \| Reinsurance Related [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Liability Fair Value	334	327
Future Contract Benefits [Member] \| Indexed Annuity And IUL Contracts [Member] \| Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Asset Fair Value	536	927
Liability Fair Value	$ 2,688	$ 2,585

Derivative Investments [Member] | Interest Rate Contracts [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Derivative Investments [Member] | Foreign currency contracts [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Derivative Investments [Member] | Equity market contracts [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Derivative Investments [Member] | Credit contracts [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Derivative Investments [Member] | Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member]

Derivative Investments [Member] | Cash Flow Hedges [Member] | Interest Rate Contracts [Member] | Designated as Hedging Instrument [Member]

Derivative Investments [Member] | Cash Flow Hedges [Member] | Foreign currency contracts [Member] | Designated as Hedging Instrument [Member]

Derivative Investments [Member] | Fair Value Hedges [Member] | Interest Rate Contracts [Member] | Designated as Hedging Instrument [Member]

Other Assets [Member] | GLB Direct Embedded Derivatives [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Other Liabilities [Member] | GLB Ceded Embedded Derivatives [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Reinsurance Related Embedded Derivatives [Member] | Reinsurance Related [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]

Future Contract Benefits [Member] | Indexed Annuity And IUL Contracts [Member] | Derivative Instruments Not Designated and Not Qualifying as Hedging Instruments [Member]