SCHEDULE IV REINSURANCE Schedule IV - Reinsurance (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	$ 22,167	$ 20,373	$ 18,075
Ceded to Other Companies	33	27	21
Assumed from Other companies	14	16	19
Net Amount	22,148	20,362	18,073
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Life insurance in force
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	173,791	168,355	149,045
Ceded to Other Companies	3,867	4,159	4,000
Assumed from Other companies	0	3	2
Net Amount	169,924	164,199	145,047
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Health insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	17,541	17,210	15,784
Ceded to Other Companies	19	14	9
Assumed from Other companies	14	12	18
Net Amount	17,536	17,208	15,793
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%
Life insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	4,626	3,163	2,291
Ceded to Other Companies	14	13	12
Assumed from Other companies	0	4	1
Net Amount	$ 4,612	$ 3,154	$ 2,280
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%

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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