Investments (Sales or Disposals and Impairments of Fixed Maturity and Equity Securities) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fixed maturity securities
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	$ 44,906,000,000	$ 45,538,000,000	$ 29,472,000,000
Gross investment gains	260,000,000	556,000,000	327,000,000
Gross investment losses	(359,000,000)	(379,000,000)	(311,000,000)
Total OTTI losses:
OTTI losses (1)	(26,000,000)	(128,000,000)	(192,000,000)
Net investment gains (losses)	(125,000,000)	49,000,000	(176,000,000)
Equity securities
Components of Sales or Disposals of Fixed Maturity and Equity Securities
Proceeds	128,000,000	144,000,000	126,000,000
Gross investment gains	46,000,000	25,000,000	23,000,000
Gross investment losses	(4,000,000)	(19,000,000)	(8,000,000)
Total OTTI losses:
OTTI losses (1)	(21,000,000)	(19,000,000)	(7,000,000)
Net investment gains (losses)	$ 21,000,000	$ (13,000,000)	$ 8,000,000

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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

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

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-Publisher FASB

-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))

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 325

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6485959&loc=d3e22529-158502

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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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