Derivatives And Other Financial Instruments (Carrying Value And Fair Values Of Other Financial Instruments) (Details) (USD $) In Millions	9 Months Ended	12 Months Ended
Sep. 30, 2011	Dec. 31, 2010
Cash And Cash Equivalents [Member]
Carrying value	$ 1,332	$ 1,543
Fair value	1,332	1,543
Restricted Cash [Member]
Carrying value	1	1
Fair value	1	1
Noncurrent Receivables [Member]
Carrying value	23	23
Fair value	23	23
Available-For-Sale Securities [Member]
Carrying value	93	93
Fair value	93	93
Short-Term Borrowings [Member]
Carrying value	57	92
Fair value	57	92
Commercial Paper [Member]
Carrying value	107
Fair value	107
Long-Term Debt Due Within One Year [Member]
Carrying value	489	231
Fair value	489	231
Long-Term Debt, Less Amount Due In One Year [Member]
Carrying value	8,658	8,842
Fair value	$ 9,138	$ 9,882

The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings.

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Chapter 4

-Paragraph 80

-Subparagraph Exhibit 4-3

-IssueDate 2006-05-01

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Chapter 4

-Paragraph 38, 40

-IssueDate 2006-05-01

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 320

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6475986&loc=d3e42546-110969

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