Goodwill - Changes in Carrying Amount of Goodwill (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 14,585
Acquisitions	50
Divestiture of business	(150)
Impact of changes in exchange rates	(78)
Goodwill, Ending Balance	14,407
Reservoir Characterization [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	3,760
Acquisitions	3
Divestiture of business
Impact of changes in exchange rates	(28)
Goodwill, Ending Balance	3,735
Drilling [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	8,337
Acquisitions	3
Divestiture of business
Impact of changes in exchange rates	(26)
Goodwill, Ending Balance	8,314
Production [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	2,488
Acquisitions	44
Divestiture of business	(150)
Impact of changes in exchange rates	(24)
Goodwill, Ending Balance	$ 2,358

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

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- Definition

Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

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Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

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