Segment Information - Schedule of Segment Reporting Information, by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting Information [Line Items]
Revenue	$ 10,248		$ 11,239
Income before taxes	1,294		2,077
Operating Segments | Reservoir Characterization
Segment Reporting Information [Line Items]
Revenue	2,550		2,979
Income before taxes	655		792
Operating Segments | Drilling
Segment Reporting Information [Line Items]
Revenue	3,963		4,331
Income before taxes	790		881
Operating Segments | Production
Segment Reporting Information [Line Items]
Revenue	3,769		3,989
Income before taxes	549		724
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	(34)		(60)
Income before taxes	(1)		(29)
Corporate
Segment Reporting Information [Line Items]
Income before taxes	(192)	[1]	(201)	[1]
Material Reconciling Items Interest Income
Segment Reporting Information [Line Items]
Income before taxes	8	[2]	7	[2]
Material Reconciling Items Interest Expense
Segment Reporting Information [Line Items]
Income before taxes	(76)	[3]	(97)	[3]
Pretax operating income
Segment Reporting Information [Line Items]
Income before taxes	1,993		2,368
Charges And Credits
Segment Reporting Information [Line Items]
Income before taxes	$ (439)	[4]

[1] Comprised principally of certain corporate expenses not allocated to the segments, stock-based compensation costs, amortization expense associated with certain intangible assets, certain centrally managed initiatives and other nonoperating items.

[2] Interest income excludes amounts which are included in the segments’ income ($5 million in 2015; $5 million in 2014).

[3] Interest expense excludes amounts which are included in the segments’ income ($6 million in 2015; $6 million in 2014).

[4] Charges and credits recorded during the first quarter of 2015 are described in detail in Note 2 to the Consolidated Financial Statements.