Investment Holding Level 4 Net Realized Capital Gains (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Available-for-sale Securities, Gross Realized Gains	$ 140	$ 124	$ 252	$ 214
Available-for-sale Securities, Gross Realized Losses	31	25	106	133
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	14	7	15	30
Foreign Currency Transaction Gain (Loss), before Tax	13	(87)	0	(131)
Realized Investment Gains (Losses)	75	53	55	(102)
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	89	60	70	(72)
Proceeds from Sale of Available-for-sale Securities	6,300	4,100	13,000	9,000
Not Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net	(40)	42	(87)	13
Reclassification out of Accumulated Other Comprehensive Income [Member] \| Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Gain (Loss) on Investments, Excluding Other than Temporary Impairments	95	92	131	51
Mortgages [Member]
Valuation Allowances and Reserves, Additions for Adjustments	2	0	2	0
Other Investments [Member]
Realized Investment Gains (Losses)	0	(17)	14	(95)
Variable Annuity [Member]
Derivative, Gain (Loss) on Derivative, Net	(18)	(17)	(86)	(48)
Macro Hedge Program [Member] \| Not Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net	(38)	(20)	(124)	(34)
Foreign Exchange Forward [Member] \| Not Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net	(17)	82	(6)	121
Other Credit Derivatives [Member] \| Not Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net	$ (5)	$ (23)	$ 5	$ (60)

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
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-Paragraph 4A
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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

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-Publisher FASB
-Name Accounting Standards Codification
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The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
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The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Amount of increase (decrease) in the allowances and reserves, which consist of the valuation and qualifying accounts that are either netted against the cost of an asset or that reflect a liability established to represent expected future costs, from adjustments.

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