v2.4.0.6

Impairments - Impairment Charges by Segment Before Tax (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges | $ 321 | $ 81 | $ 469
Alaska [Member] |  |  |
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges | 2 | 6 |
Lower 48 and Latin America [Member] |  |  |
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges | 71 | 19 | 56
Canada [Member] |  |  |
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges | 253 | 13 | 296
Europe [Member] |  |  |
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges | (37) | 43 | 104
Asia Pacific and Middle East [Member] |  |  |
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges |  |  | 12
Corporate [Member] |  |  |
Impaired Assets to be Disposed of by Method Other than Sale [Line Items] |  |  |
Asset Impairment Charges | $ 32 |  | $ 1

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- Definition The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value. + References Reference 1: 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-Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 45, 46, 47 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 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FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 4: 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=8077374&loc=d3e2420-110228 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Details
Name: | us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration