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	$ 205,628
Interest rate contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	133,737
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	68,727
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	205,628	$ 161,115
Asset Fair Value	6,096	4,261
Liability Fair Value	5,821	4,621
Derivative investments [Member] | Interest rate contracts [Member] | Non-Qualifying Hedging [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] | Non-Qualifying Hedging [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] | Non-Qualifying Hedging [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	68,727	43,283
Asset Fair Value	2,211	1,442
Liability Fair Value	1,070	664
Derivative investments [Member] | Credit contracts [Member] | Non-Qualifying Hedging [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	54	55
Derivative investments [Member] | Cash Flow Hedges [Member] | Qualifying Hedges [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	4,105	4,048
Asset Fair Value	489	299
Liability Fair Value	38	63
Derivative investments [Member] | Cash Flow Hedges [Member] | Interest rate contracts [Member] | Qualifying Hedges [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	1,234	1,174
Asset Fair Value	169	108
Liability Fair Value	2	12
Derivative investments [Member] | Cash Flow Hedges [Member] | Foreign currency contracts [Member] | Qualifying Hedges [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] | Qualifying Hedges [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	530	546
Liability Fair Value	301	202
Other Assets [Member] | GLB Direct Embedded Derivatives [Member] | Non-Qualifying Hedging [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] | Non-Qualifying Hedging [Member]
Outstanding derivative instruments with off-balance-sheet risks
Asset Fair Value	1,105	60
Liability Fair Value		510
Reinsurance Related Embedded Derivatives [Member] | Embedded derivatives - Reinsurance related [Member] | Non-Qualifying Hedging [Member]
Outstanding derivative instruments with off-balance-sheet risks
Liability Fair Value	476	375
Future Contract Benefits [Member] | Indexed Annuity And IUL Contracts [Member] | Non-Qualifying Hedging [Member]
Outstanding derivative instruments with off-balance-sheet risks
Asset Fair Value	536	927
Liability Fair Value	$ 2,688	$ 2,585