Fair Value Measurements Level 4 Significant Unobservable Inputs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	$ 25,625		$ 25,625		$ 24,657
Credit standing adjustment assumption net of reinsurance [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative, Gain (Loss) on Derivative, Net	0	$ 0	$ (1)	$ (1)
Derivative Financial Instruments, Assets [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Derivative instruments are fair valued using pricing valuation models for OTC derivatives that utilize independent market data inputs, quoted market prices for exchange-traded and OTC-cleared derivatives, or independent broker quotations. Excluding embedded and reinsurance related derivatives, as of September 30, 2016 and December 31, 2015, 97% and 94%, respectively, of derivatives, based upon notional values, were priced by valuation models, including discounted cash flow models and option-pricing models that utilize present value techniques, or quoted market prices. The remaining derivatives were priced by broker quotations.
Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	325	164	$ 325	164	139	$ 171	$ 285	$ 112
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		31		32
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	1	28	1	29
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(1)	2	5
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	165	57	226	317
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	3	6	12	16
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	11	200	27	226
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	10	1	16	7
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	7	1	23	56
Available-for-sale Securities, Debt Securities	1,776		1,776		1,625
Level 3 [Member] | Reinsurance Recoverable [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	98		98			106
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(12)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	(12)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	4
Level 3 [Member] | US Macro Hedge Program [Member] | Equity options [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	195		$ 195		$ 179
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Option model		Option model
Fair value measurements significant assumptions			Equity volatility		Equity volatility
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Level 3 [Member] | Interest Rate Contract [Member] | Interest Rate Swap [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	(34)		$ (34)		$ (30)
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Discounted  cash flows		Discounted  cash flows
Fair value measurements significant assumptions			Swap curve  beyond 30 years		Swap curve  beyond 30 years
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Level 3 [Member] | US GMWB Hedging Instruments [Member] | Other Contract [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	142		$ 142		$ 131
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Discounted  cash flows		Discounted  cash flows
Fair value measurements significant assumptions			Equity volatility		Equity volatility
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Level 3 [Member] | US GMWB Hedging Instruments [Member] | Variance Swap [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	(36)		$ (36)		$ (31)
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Option model		Option model
Fair value measurements significant assumptions			Equity volatility		Equity volatility
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Level 3 [Member] | US GMWB Hedging Instruments [Member] | Equity options [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	25		$ 25		$ 35
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Option model		Option model
Fair value measurements significant assumptions			Equity volatility		Equity volatility
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Level 3 [Member] | Maximum [Member] | Macro Hedge Program [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			27.00%
Level 3 [Member] | Maximum [Member] | GMWB Hedging Instruments [Member] | Other Contract [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			30.00%		40.00%
Level 3 [Member] | Maximum [Member] | GMWB Hedging Instruments [Member] | Variance Swap [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			23.00%		21.00%
Level 3 [Member] | Maximum [Member] | GMWB Hedging Instruments [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			29.00%		29.00%
Level 3 [Member] | Maximum [Member] | US Macro Hedge Program [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate					28.00%
Level 3 [Member] | Maximum [Member] | Interest Rate Contract [Member] | Interest Rate Swap [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Unobservable Swap Curve			2.00%		3.00%
Level 3 [Member] | Minimum [Member] | Macro Hedge Program [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			15.00%
Level 3 [Member] | Minimum [Member] | GMWB Hedging Instruments [Member] | Other Contract [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			12.00%		10.00%
Level 3 [Member] | Minimum [Member] | GMWB Hedging Instruments [Member] | Variance Swap [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			20.00%		19.00%
Level 3 [Member] | Minimum [Member] | GMWB Hedging Instruments [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate			27.00%		27.00%
Level 3 [Member] | Minimum [Member] | US Macro Hedge Program [Member] | Equity options [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Assumptions, Expected Volatility Rate					14.00%
Level 3 [Member] | Minimum [Member] | Interest Rate Contract [Member] | Interest Rate Swap [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Unobservable Swap Curve			2.00%		3.00%
Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	0	47	$ 0	47	$ 2	0	72	84
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		1		2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings				(4)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		1		1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases			1	5
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements		25		23
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales			1	5
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		1	$ 2	11
Level 3 [Member] | CMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Discounted cash flows		Discounted cash flows
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Level 3 [Member] | CMBS [Member] | Maximum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			1274.00%		1505.00%
Level 3 [Member] | CMBS [Member] | Minimum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			11.00%		31.00%
Level 3 [Member] | CMBS [Member] | Weighted Average [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			196.00%		230.00%
Level 3 [Member] | Corporate [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Discounted cash flows		Discounted cash flows
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Level 3 [Member] | Corporate [Member] | Maximum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			1364.00%		800.00%
Level 3 [Member] | Corporate [Member] | Minimum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			156.00%		63.00%
Level 3 [Member] | Corporate [Member] | Weighted Average [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			435.00%		290.00%
Level 3 [Member] | Municipal [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Discounted cash flows		Discounted cash flows
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Level 3 [Member] | Municipal [Member] | Maximum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Treasury Yield			326.00%		193.00%
Level 3 [Member] | Municipal [Member] | Minimum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Treasury Yield			195.00%		193.00%
Level 3 [Member] | Municipal [Member] | Weighted Average [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Treasury Yield			224.00%		193.00%
Level 3 [Member] | RMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements valuation techniques			Discounted cash flows		Discounted cash flows
Level 3 [Member] | RMBS [Member] | Maximum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			1736.00%		1696.00%
Fair Value Inputs, Prepayment Rate			20.00%		20.00%
Fair Value Inputs, Probability of Default			10.00%		10.00%
Fair Value Inputs, Loss Severity			0.00%		0.00%
Level 3 [Member] | RMBS [Member] | Minimum [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			43.00%		30.00%
Fair Value Inputs, Prepayment Rate			0.00%		0.00%
Fair Value Inputs, Probability of Default			1.00%		1.00%
Fair Value Inputs, Loss Severity			0.00%		0.00%
Level 3 [Member] | RMBS [Member] | Weighted Average [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Inputs Counterparty Credit Risk			191.00%		172.00%
Fair Value Inputs, Prepayment Rate			3.00%		3.00%
Fair Value Inputs, Probability of Default			5.00%		6.00%
Fair Value Inputs, Loss Severity			0.00%		0.00%
Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	114		$ 114		$ 123
Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	23,735		$ 23,735		$ 22,909
Withdrawal Utilization [Member] | Level 3 [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Withdrawal Utilization [Member] | Level 3 [Member] | Maximum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			100.00%		100.00%
Withdrawal Utilization [Member] | Level 3 [Member] | Minimum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			20.00%		20.00%
Withdrawal Rates [Member] | Level 3 [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Withdrawal Rates [Member] | Level 3 [Member] | Maximum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			8.00%		8.00%
Withdrawal Rates [Member] | Level 3 [Member] | Minimum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			0.00%		0.00%
Spread [Member] | Level 3 [Member] | CMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Spread (encompasses prepayment, default risk and loss severity)		Spread (encompasses prepayment, default risk and loss severity)
Spread [Member] | Level 3 [Member] | Corporate [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Spread		Spread
Spread [Member] | Level 3 [Member] | Municipal [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Spread		Spread
Spread [Member] | Level 3 [Member] | RMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Spread		Spread
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Prepayment Rate [Member] | Level 3 [Member] | RMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Constant prepayment rate		Constant prepayment rate
Fair Value Measurements, Sensitivity Analysis, Description			Decrease [4]		Decrease [4]
Probability of Default [Member] | Level 3 [Member] | RMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Constant default rate		Constant default rate
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Loss Severity [Member] | Level 3 [Member] | RMBS [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair value measurements significant assumptions			Loss severity		Loss severity
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Lapse Rates [Member] | Level 3 [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Sensitivity Analysis, Description			Decrease		Decrease
Lapse Rates [Member] | Level 3 [Member] | Maximum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			75.00%		75.00%
Lapse Rates [Member] | Level 3 [Member] | Minimum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			0.00%		0.00%
Reset Elections [Member] | Level 3 [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Reset Elections [Member] | Level 3 [Member] | Maximum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			75.00%		75.00%
Reset Elections [Member] | Level 3 [Member] | Minimum [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			20.00%		20.00%
Equity Volatility [Member] | Level 3 [Member] | Living Benefits Required to be Fair Valued and the GMWB Reinsurance Derivative [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Fair Value Measurements, Sensitivity Analysis, Description			Increase		Increase
Equity Volatility [Member] | Level 3 [Member] | Maximum [Member] | GMWB Hedging Instruments [Member] | Other Contract [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			30.00%		40.00%
Equity Volatility [Member] | Level 3 [Member] | Minimum [Member] | GMWB Hedging Instruments [Member] | Other Contract [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input [Abstract]
Range of Values-Unobservable Inputs			12.00%		10.00%
Foreign Government Debt Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	338		$ 338		$ 331
Foreign Government Debt Securities [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	20		20		17
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	318		318		314
Asset-backed Securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,049		1,049		846
Asset-backed Securities [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	20		20		5
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,029		1,029		841
RMBS [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,782		1,782		1,503
RMBS [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	743		743		628
RMBS [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
RMBS [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,039		1,039		875
RMBS [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	743		743		628
Municipal [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,289		1,289		1,132
Municipal [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	79		79		49
Municipal [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
Municipal [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,210		1,210		1,083
Municipal [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Non-Broker Priced [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	61		61		31
Corporate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	15,593		15,593		15,175
Corporate [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	635		635		534
Corporate [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
Corporate [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	14,958		14,958		14,641
Corporate [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Non-Broker Priced [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	280		280		213
CMBS [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	2,269		2,269		1,964
CMBS [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	23		23		62
CMBS [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
CMBS [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	2,246		2,246		1,902
CMBS [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	17		17		61
Collateralized Debt Obligations [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	1,209		1,209		1,408
Collateralized Debt Obligations [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	256		256		330
Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	0		0		0
Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities, Debt Securities	953		953		1,078
Available-for-sale Securities [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	1,776	1,615	1,776	1,615	1,625	1,786	1,722	2,025
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(11)	(12)	(12)	(13)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	(11)	(10)	(19)	(14)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	31	(12)	34	(34)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	155	46	371	132
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	46	48	236	169
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	33	67	72	162
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	56	27	378	106
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	162	43	305	269
Available-for-sale Securities [Member] | Foreign Government Debt Securities [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	20	16	20	16	17	18	15	30
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	1	(1)	3	(3)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	5		8	3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	1		3	2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	3	1	5	15
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		3		3
Available-for-sale Securities [Member] | Asset-backed Securities [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	20	5	20	5	5	7	14	82
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)				(2)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	17		17	22
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	1		1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	2		2	6
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			5	1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	1	9	4	92
Available-for-sale Securities [Member] | RMBS [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	743	597	743	597	628	690	662	734
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings				(1)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	5	(3)	3	(2)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	93	22	241	68
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	37	33	113	91
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	8	51	8	108
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			2	16
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			10	19
Available-for-sale Securities [Member] | Municipal [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	79	50	79	50	49	73	49	54
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	2	1	6	(4)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	4		16
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3			8
Available-for-sale Securities [Member] | Corporate [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	635	540	635	540	534	717	547	646
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(11)	(12)	(12)	(11)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	(11)	(10)	(18)	(12)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	25		29	(26)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	22	19	56	22
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	4	4	41	20
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	20	15	55	30
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	56	24	363	82
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	158	29	233	122
Available-for-sale Securities [Member] | CMBS [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	23	74	23	74	62	15	87	119
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)				(1)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		(1)	(1)	(2)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	14	5	33	17
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	3	12	11	31
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales			2	3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3				4
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	3	5	58	30
Available-for-sale Securities [Member] | Collateralized Debt Obligations [Member] | Level 3 [Member] | Fixed Maturities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	256	333	256	333	$ 330	$ 266	$ 348	$ 360
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)				(1)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			(1)	(1)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(2)	(8)	(6)	5
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	$ 8	$ 7	$ 67	25
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3				$ 6