Derivative Instruments (Outstanding Derivative Instruments With Off-Balance-Sheet Risks) (Details) - USD ($) $ in Millions		Jun. 30, 2018	Dec. 31, 2017
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		$ 128,031
Interest rate contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	[1]	94,820
Foreign currency contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts	[2]	2,162
Equity market contracts [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		31,049
Total Derivative Instruments [Member]
Outstanding derivative instruments with off-balance-sheet risks
Notional Amounts		128,031	$ 110,350
Asset Fair Value		2,456	2,563
Liability Fair Value		2,400	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]	90,678	72,937
Asset Fair Value	[3]	393	657
Liability Fair Value	[3]	195	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]	134	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]	31,049	31,090
Asset Fair Value	[3]	521	562
Liability Fair Value	[3]	427	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		4,895	4,811
Asset Fair Value		178	125
Liability Fair Value		94	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]	2,867	3,007
Asset Fair Value	[3]	85	46
Liability Fair Value	[3]	21	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]	2,028	1,804
Asset Fair Value	[3]	93	79
Liability Fair Value	[3]	73	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]	1,275	1,438
Asset Fair Value	[3]	46	254
Liability Fair Value	[3]	128	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]	1,248	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]	41	51
Liability Fair Value	[4],[5]	131	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]	25	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]	29	11
Liability Fair Value	[4],[7]	$ 1,400	$ 1,418

[1] As of June 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 June 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.