Investments in fixed maturity securities - fair value by segment (Detail) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Investments in securities with fixed maturities [Line Items]
Fair Value	$ 35,854	$ 34,883
Insurance and Other [Member]
Investments in securities with fixed maturities [Line Items]
Fair Value	34,813	33,803
Finance and Financial Products [Member]
Investments in securities with fixed maturities [Line Items]
Fair Value	$ 1,041	$ 1,080

For an unclassified balance sheet, this item represents investments in debt securities having predetermined or determinable maturity dates.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 7
-Section 03
-Paragraph 1
-Subparagraph a

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Name:	us-gaap_MarketableSecuritiesFixedMaturities
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant