Goodwill - Changes in Carrying Amount of Goodwill (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 14,706us-gaap_Goodwill	$ 14,585us-gaap_Goodwill
Acquisitions	837us-gaap_GoodwillAcquiredDuringPeriod	343us-gaap_GoodwillAcquiredDuringPeriod
Divestiture of business		(150)
Other	(56)us-gaap_GoodwillOtherChanges	(72)us-gaap_GoodwillOtherChanges
Goodwill, Ending Balance	15,487us-gaap_Goodwill	14,706us-gaap_Goodwill
Operating Segments \| Reservoir Characterization
Goodwill [Line Items]
Goodwill, Beginning Balance	3,737	3,760
Acquisitions	15	4
Reallocation	83
Other	(23)	(27)
Goodwill, Ending Balance	3,812	3,737
Operating Segments \| Drilling
Goodwill [Line Items]
Goodwill, Beginning Balance	8,315	8,337
Acquisitions	271	3
Reallocation	(83)
Other	(15)	(25)
Goodwill, Ending Balance	8,488	8,315
Operating Segments \| Production
Goodwill [Line Items]
Goodwill, Beginning Balance	2,654	2,488
Acquisitions	551	336
Divestiture of business		(150)
Other	(18)	(20)
Goodwill, Ending Balance	$ 3,187	$ 2,654

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=35741047&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

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

+ Details

Name:	us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_GoodwillLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	us-gaap_GoodwillOtherChanges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the 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 (g)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 25

-Paragraph 16

-URI http://asc.fasb.org/extlink&oid=34752592&loc=d3e961-128460

+ Details

Name:	us-gaap_GoodwillPurchaseAccountingAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ Details

Name:	us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: