Derivative Instruments (Outstanding Derivative Instruments With Off-Balance-Sheet Risks) (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		$ 136,995
Interest rate contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	[1]	104,390
Foreign currency contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	[2]	2,001
Equity market contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		30,604
Total Derivative Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		136,995	$ 110,350
Asset Fair Value		2,622	2,563
Liability Fair Value		2,348	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]	99,814	72,937
Asset Fair Value	[3]	498	657
Liability Fair Value	[3]	165	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]	114	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]	30,604	31,090
Asset Fair Value	[3]	656	562
Liability Fair Value	[3]	374	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		5,024	4,811
Asset Fair Value		96	125
Liability Fair Value		176	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]	3,137	3,007
Asset Fair Value	[3]	49	46
Liability Fair Value	[3]	37	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]	1,887	1,804
Asset Fair Value	[3]	47	79
Liability Fair Value	[3]	139	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]	1,439	1,438
Asset Fair Value	[3]	200	254
Liability Fair Value	[3]	142	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],[5]	1,110	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]	45	51
Liability Fair Value	[4],[5]	111	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]	34	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]	17	11
Liability Fair Value	[4],[7]	$ 1,346	$ 1,418

[1] As of March 31, 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 March 31, 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.