Financial Instruments (Estimated Fair Value of Debt, Financing and Capital Lease Obligations) (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Fair Value Disclosures [Abstract]
Current and long-term debt, financing and capital lease obligations, Carrying amount	$ 18,529	$ 20,191
Current and long-term debt, financing and capital lease obligations, Estimated fair value	$ 16,707	$ 20,007

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13,16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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