Investments (Net realized investment gains (losses)) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net realized investment gains (losses)	$ 0	$ (14)	$ 10	$ 32
Fixed maturity securities [Member]
Gross realized gains	36	20	69	73
Gross realized losses	(48)	(39)	(69)	(54)
Net realized investment gains (losses)	(12)	(19)	0	19
Equity securities [Member]
Gross realized gains	0	0	1	5
Gross realized losses	(1)	0	(2)	0
Net realized investment gains (losses)	(1)	0	(1)	5
Derivative [Member]
Net realized investment gains (losses)	11	1	10	1
Short term investments and other [Member]
Net realized investment gains (losses)	$ 2	$ 4	$ 1	$ 7

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity 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)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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