Derivative Instruments (Outstanding Derivative Instruments With Off-Balance-Sheet Risks) (Details) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		$ 121,372
Interest rate contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	[1]	94,233
Foreign currency contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	[2]	2,172
Equity market contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		24,967
Total Derivative Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		121,372	$ 110,350
Asset Fair Value		2,834	2,563
Liability Fair Value		2,382	2,563
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	[3]	90,138	72,937
Asset Fair Value	[3]	318	657
Liability Fair Value	[3]	233	127
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	[3]	87	22
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	[3]	24,967	31,090
Asset Fair Value	[3]	534	562
Liability Fair Value	[3]	140	557
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	[3]		52
Derivative investments [Member] | Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		4,912	4,811
Asset Fair Value		225	125
Liability Fair Value		113	163
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	[3]	2,827	3,007
Asset Fair Value	[3]	121	46
Liability Fair Value	[3]	42	84
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	[3]	2,085	1,804
Asset Fair Value	[3]	104	79
Liability Fair Value	[3]	71	79
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	[3]	1,268	1,438
Asset Fair Value	[3]	30	254
Liability Fair Value	[3]	112	174
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	[4]	1,648	903
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	[4],[5]	35	51
Liability Fair Value	[4],[5]	193	67
Reinsurance Related Embedded Derivatives [Member] | Embedded derivatives - 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	[6]	20	57
Future Contract Benefits [Member] | Indexed Annuity And 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	[4],[7]	44	11
Liability Fair Value	[4],[7]	$ 1,571	$ 1,418

[1] As of September 30, 2018, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was April 2067.

[2] As of September 30, 2018, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was September 2049.

[3] Reported in derivative investments and other liabilities on our Consolidated Balance Sheets.

[4] Reported in other assets on our Consolidated Balance Sheets.

[5] Reported in other liabilities on our Consolidated Balance Sheets.

[6] Reported in reinsurance related embedded derivatives on our Consolidated Balance Sheets.

[7] Reported in future contract benefits on our Consolidated Balance Sheets.