Investments (Sales or Disposals and Impairments of Fixed Maturity and Equity Securities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	$ 3,927	$ 1,359	$ 9,324	$ 4,379
Gross investment gains	9	15	134	126
Gross investment losses	(61)	(8)	(97)	(38)
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	(9)	(13)	(23)	(48)
Net investment gains (losses)	(61)	(6)	14	40
Credit-Related [Member]
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	(9)	(13)	(17)	(35)
Other Other Than Temporary Investment Losses [Member]
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	0	0	(6)	(13)
Fixed maturity securities [Member]
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	3,914	1,354	9,269	4,348
Gross investment gains	9	13	124	117
Gross investment losses	(59)	(7)	(91)	(33)
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	(9)	(13)	(20)	(42)
Net investment gains (losses)	(59)	(7)	13	42
Fixed maturity securities [Member] \| Credit-Related [Member]
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	(9)	(13)	(17)	(35)
Fixed maturity securities [Member] \| Other Other Than Temporary Investment Losses [Member]
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	0	0	(3)	(7)
Equity Securities [Member]
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	13	5	55	31
Gross investment gains	0	2	10	9
Gross investment losses	(2)	(1)	(6)	(5)
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	0	0	(3)	(6)
Net investment gains (losses)	(2)	1	1	(2)
Equity Securities [Member] \| Credit-Related [Member]
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	0	0	0	0
Equity Securities [Member] \| Other Other Than Temporary Investment Losses [Member]
Total OTTI losses recognized in earnings:
Total OTTI losses recognized in earnings	$ 0	$ 0	$ (3)	$ (6)

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

+ References

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 and excluding other than temporary impairments (OTTI), if any, recognized elsewhere.

+ References

No definition available.

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 8B

-URI http://asc.fasb.org/extlink&oid=27724398&loc=SL6284393-111563

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- Definition

The cash inflow associated with the sale of insurance policy investment assets during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

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-Name Accounting Standards Codification

-Glossary Investing Activities

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.3(a))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 3

-Subparagraph a

-Article 7

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