Fair Value of Assets and Liabilities (Details 4) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	$ 3	$ (3)	$ 13	$ (30)
Gains (losses) for Level 3 liabilities still held at the balance sheet date, included in earnings	0	7	3	(8)
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets and liabilities	9	3	23	(26)
Gain (Loss) on Investments
Gains (losses) included in net income for Level 3 assets and liabilities:
Total realized and unrealized gains (losses) included in net income, recurring Level 3 assets and liabilities	3	4	16	(38)
Realized capital gains and losses
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	(1)	(9)		(38)
Gain reclassified from AOCI into income (net investment income)
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	4	6	14	8
Interest credited to contractholder funds
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	(1)	(7)	(6)	(6)
Life and annuity contract benefits
Gains (losses) included in net income for Level 3 assets and liabilities:
Change in unrealized gain (loss)	1	14	8	(2)
Derivatives embedded in life and annuity contracts
Gains (losses) included in net income for Level 3 assets and liabilities:
Gains (losses) for Level 3 liabilities still held at the balance sheet date, included in earnings	0	7	3	(8)
Municipal
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	(3)	1	(3)	1
Corporate
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	0	3	0	1
Fixed income securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	(3)	4	(3)	2
Equity securities
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	4	(8)	14	(32)
Free-standing derivatives, net
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	2	1	3	0
Other assets
Gains (losses) included in net income for Level 3 assets and liabilities:
Recurring Level 3 assets	$ 0	$ 0	$ (1)	$ 0

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This item represents the amount of the total change in unrealized (holding) gains or losses for the period which are included in the statement of income (or changes in net assets). Such unrealized (holding) gains or losses relate to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

No definition available.

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This item represents the amount of the total realized and unrealized gains or losses for the period which are included in the statement of income (or changes in net assets); the fair value of which assets and liabilities was or is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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