Derivative Instruments Level 4 Derivative Balance Sheet Classification (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 39,644	$ 41,099
Derivative, Fair Value, Net	(405)	(475)
Derivative Asset, Fair Value, Gross Asset	633	749
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	741	890
Derivative Liability, Fair Value, Gross Liability	(1,053)	(1,091)
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	1,146	1,365
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	551	588
Derivative, Collateral, Obligation to Return Cash	115	74
Derivative Asset, Fair Value of Collateral	41	101
Derivative Asset, Fair Value, Amount Offset Against Collateral	41	60
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	265	396
Derivative, Collateral, Right to Reclaim Cash	171	118
Derivative Liability, Fair Value of Collateral	785	655
Derivative Liability, Fair Value, Amount Offset Against Collateral	3	40
Other Policyholder Funds and Benefits Payable [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,797	13,164
Derivative, Fair Value, Net	(93)	(274)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(93)	(274)
Reinsurance Recoverable [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,333	3,584
Derivative, Fair Value, Net	108	141
Derivative Asset, Fair Value, Gross Asset	108	141
Derivative Liability, Fair Value, Gross Liability	0	0
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	12,865	11,498
Derivative, Fair Value, Net	(617)	(577)
Derivative Asset, Fair Value, Gross Asset	375	424
Derivative Liability, Fair Value, Gross Liability	(992)	(1,001)
Other Investments [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,614	12,732
Derivative, Fair Value, Net	197	235
Derivative Asset, Fair Value, Gross Asset	258	325
Derivative Liability, Fair Value, Gross Liability	(61)	(90)
Fixed Maturities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	35	121
Derivative, Fair Value, Net	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	37,810	39,141
Derivative, Fair Value, Net	(395)	(466)
Derivative Asset, Fair Value, Gross Asset	729	871
Derivative Liability, Fair Value, Gross Liability	(1,124)	(1,337)
Currency Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	37	382
Derivative, Fair Value, Net	0	36
Derivative Asset, Fair Value, Gross Asset	0	36
Derivative Liability, Fair Value, Gross Liability	0	0
Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,834	1,958
Derivative, Fair Value, Net	(10)	(9)
Derivative Asset, Fair Value, Gross Asset	12	19
Derivative Liability, Fair Value, Gross Liability	(22)	(28)
Derivative Financial Instruments, Liabilities [Member] | Other Liabilities [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(617)	(577)
Derivative Financial Instruments, Assets [Member] | Other Investments [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	197	235
Three Win Related Foreign Currency Swaps [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	804	804
Derivative, Fair Value, Net	(255)	(263)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(255)	(263)
Credit Default Swap, Buying Protection [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	85	131
Derivative, Fair Value, Net	(3)	(3)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(3)	(3)
Credit Default Swap, Selling Protection [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	377	458
Derivative, Fair Value, Net	2	4
Derivative Asset, Fair Value, Gross Asset	8	5
Derivative Liability, Fair Value, Gross Liability	(6)	(1)
Credit Derivatives in Offsetting Positions [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	590	1,006
Derivative, Fair Value, Net	2	(1)
Derivative Asset, Fair Value, Gross Asset	10	16
Derivative Liability, Fair Value, Gross Liability	(8)	(17)
Equity Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	100
Derivative, Fair Value, Net	0	0
Derivative Asset, Fair Value, Gross Asset	0	33
Derivative Liability, Fair Value, Gross Liability	0	(33)
GMWB Product Derivatives [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	11,797	13,114
Derivative, Fair Value, Net	(93)	(241)
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	(93)	(241)
GMWB Reinsurance [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,450	2,709
Derivative, Fair Value, Net	51	73
Derivative Asset, Fair Value, Gross Asset	51	73
Derivative Liability, Fair Value, Gross Liability	0	0
Coinsurance and Modified Coinsurance Reinsurance Contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	57	68
Derivative Asset, Fair Value, Gross Asset	57	68
Derivative Liability, Fair Value, Gross Liability	0	0
Invested Assets Suppoting Modco	882	875
GMWB Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	9,391	10,256
Derivative, Fair Value, Net	65	94
GMWB Hedging Instruments [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	9,391	10,256
Derivative, Fair Value, Net	65	94
Derivative Asset, Fair Value, Gross Asset	130	190
Derivative Liability, Fair Value, Gross Liability	(65)	(96)
Interest Rate Contract [Member] | Other Liabilities [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(387)
Interest Rate Contract [Member] | Other Investments [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	1	30
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,240	2,774
Derivative, Fair Value, Net	(387)	(411)
Derivative Asset, Fair Value, Gross Asset	281	249
Derivative Liability, Fair Value, Gross Liability	(668)	(660)
Foreign Exchange Contract [Member] | Other Liabilities [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(264)
Foreign Exchange Contract [Member] | Other Investments [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	(2)	4
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(11)
Macro Hedge Program [Member] | Other Liabilities [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	8	50
Macro Hedge Program [Member] | Other Investments [Member]
Derivative, Fair Value, Amount Offset Against Collateral, Net [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	158	128
Macro Hedge Program [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,157	6,532
Derivative, Fair Value, Net	166	178
Derivative Asset, Fair Value, Gross Asset	192	201
Derivative Liability, Fair Value, Gross Liability	(26)	(23)
Fair Value Hedging [Member] | Equity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Net	(41)	(27)
Cash Flow Hedging [Member] | Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,656	1,794
Derivative, Fair Value, Net	1	7
Derivative Asset, Fair Value, Gross Asset	6	9
Derivative Liability, Fair Value, Gross Liability	(5)	(2)
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	178	164
Derivative, Fair Value, Net		(16)
Derivative Asset, Fair Value, Gross Asset	6	10
Derivative Liability, Fair Value, Gross Liability	$ (17)	$ (26)