The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6390789&loc=d3e2420-110228

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 Statement of Financial Accounting Standard (FAS)

-Number 144

-Paragraph 45, 46, 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Financial Instrument Fair Value by Balance Sheet Grouping (Details) (USD $) In Millions					3 Months Ended		9 Months Ended
	Sep. 30, 2011 Carrying (Reported) Amount, Fair Value Disclsure [Member]	Dec. 31, 2010 Carrying (Reported) Amount, Fair Value Disclsure [Member]	Sep. 30, 2011 Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2010 Estimate of Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2011 Fair Value, Inputs, Level 3 [Member]	Sep. 30, 2010 Fair Value, Inputs, Level 3 [Member]	Sep. 30, 2011 Fair Value, Inputs, Level 3 [Member]	Sep. 30, 2010 Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Assets, Balance Sheet Grouping [Abstract]
Long-term receivables	$ 127	$ 203	$ 127	$ 199
Liabilities Balance Sheet Groupings [Abstract]
Long-term debt and related current maturities	7,395	6,278	8,395	6,835
Fair Value By Balance Sheet Grouping Paragraph Details [Line Items]
Non-Financial assets					128	13	143	31
Asset Impairment Charges					$ 74	$ 12	$ 85	$ 29