Investments (Net realized investment gains (losses)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Net realized investment gains (losses)	$ 10	$ 46
Fixed maturity securities [Member]
Gross realized gains	33	53
Gross realized losses	(21)	(15)
Net realized investment gains (losses)	12	38
Equity securities [Member]
Gross realized gains	1	5
Gross realized losses	(1)	0
Net realized investment gains (losses)	0	5
Derivative [Member]
Net realized investment gains (losses)	(1)	0
Short term investments and other [Member]
Net realized investment gains (losses)	$ (1)	$ 3

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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