Intangible Assets (Estimated Amortization Expense Over Next Five Years) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2013	$ 49
2014	45
2015	40
2016	35
2017	33
Total	202
Intangible Assets Arising from Insurance Contracts Acquired in Business Combination, Amortization Expense, Fiscal Year Maturity [Abstract]
2013	67
2014	58
2015	51
2016	45
2017	42
Total	$ 263

Total amortization expected to be recognized for finite lived intangible assets over the next five years.

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- Definition

Total amortization expense estimated to be recorded over the next five years for intangible assets arising from insurance contracts acquired in business combinations

+ References

No definition available.

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- Definition

Amount of amortization expense expected to be recognized during the next fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

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Amount of amortization expense expected to be recognized during the fifth fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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Amount of amortization expense expected to be recognized during the fourth fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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Amount of amortization expense expected to be recognized during the third fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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Amount of amortization expense expected to be recognized during the second fiscal year following the latest fiscal year for assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Amount of amortization expense expected to be recognized during the next fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section S99

-Paragraph 2

-Subparagraph (3)

-URI http://asc.fasb.org/extlink&oid=6784649&loc=d3e569990-122904

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Amount of amortization expense expected to be recognized during the fifth fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

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Amount of amortization expense expected to be recognized during the fourth fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

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Amount of amortization expense expected to be recognized during the third fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

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Amount of amortization expense expected to be recognized during the second fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

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