The current portion, due within one year or one operating cycle, if longer, of deposits held other than customer deposits.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DepositLiabilityCurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Customer Deposits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		48 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2007	Dec. 31, 2010
Customer Deposits
Long-term purchase and supply agreement period, years			6
Customer deposit agreements					$ 937
Credit memoranda	7	8	21	76
Customer deposit liabilities	$ 7		$ 7			$ 27