Investments (Schedule Of Components Of Restricted Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Investments [Abstract]
Trust funds	$ 10,605	$ 9,940
Deposits with non-U.S. regulatory authorities	2,126	2,240
Deposits with U.S. regulatory authorities	1,293	1,307
Assets pledged under reverse repurchase agreements	1,401	1,251
Other pledged assets	451	364
Total restricted assets	$ 15,876	$ 15,102

Restricted assets that are deposits with non-US regulatory authorities.

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- Definition

Restricted assets that are deposits with US regulatory authorities.

+ References

No definition available.

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- Definition

Restricted assets that are other pledged assets.

+ References

No definition available.

+ Details

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- Definition

Restricted assets that are trust funds.

+ References

No definition available.

+ Details

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- Details

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- Definition

Cash and investments whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet.

+ References

No definition available.

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- Definition

The carrying value of securities purchased to be resold in reverse repurchase transactions as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(m)(2)(i))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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