Schedule IV (SUPPLEMENTAL INFORMATION CONCERNING REINSURANCE) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental Schedule of Reinsurance Premiums for Insurance Companies [Abstract]
Direct Amount	$ 17,802	$ 17,534	$ 15,780
Ceded To Other Companies	5,427	5,496	5,792
Assumed From Other Companies	3,302	3,349	3,516
Net Amount	$ 15,677	$ 15,387	$ 13,504
Percentage of Amount Assumed to Net	21.00%	22.00%	26.00%

Amount of premiums assumed from other companies.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=6588446&loc=d3e574992-122915

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Amount of premiums ceded to other companies.

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