Segment Information - Schedule of Segment Reporting Information, by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Segment Reporting Information [Line Items]
Revenue	$ 12,054		$ 11,182		$ 23,294		$ 21,752
Income before taxes	2,327		2,673		4,403		4,291
Operating Segments | Reservoir Characterization
Segment Reporting Information [Line Items]
Revenue	3,095		3,067		5,947		5,868
Income before taxes	918		912		1,698		1,641
Operating Segments | Drilling
Segment Reporting Information [Line Items]
Revenue	4,653		4,239		8,984		8,301
Income before taxes	981		800		1,861		1,525
Operating Segments | Production
Segment Reporting Information [Line Items]
Revenue	4,344		3,926		8,460		7,684
Income before taxes	725		625		1,462		1,181
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	(38)		(50)		(97)		(101)
Income before taxes	(3)		(59)		(32)		(104)
Pretax operating income
Segment Reporting Information [Line Items]
Income before taxes	2,621		2,278		4,989		4,243
Corporate & other
Segment Reporting Information [Line Items]
Income before taxes	(216)	[1]	(181)	[1]	(418)	[1]	(348)	[1]
Interest income
Segment Reporting Information [Line Items]
Income before taxes	8	[2]	4	[2]	15	[3]	9	[3]
Interest expense
Segment Reporting Information [Line Items]
Income before taxes	(86)	[4]	(92)	[4]	(183)	[5]	(185)	[5]
Charges & credits
Segment Reporting Information [Line Items]
Income before taxes			$ 664	[6]			$ 572	[6]

[1] Comprised principally of certain corporate expenses not allocated to the segments, interest on postretirement medical benefits, stock-based compensation costs, amortization expense associated with certain intangible assets and other nonoperating items.

[2] Interest income excludes amounts which are included in the segments’ income ($5 million in 2014; $2 million in 2013).

[3] Interest income excludes amounts which are included in the segments’ income ($10 million in 2014; $2 million in 2013).

[4] Interest expense excludes amounts which are included in the segments’ income ($4 million in 2014; $6 million in 2013).

[5] Interest expense excludes amounts which are included in the segments’ income ($10 million in 2014; $12 million in 2013).

[6] See Note 2 – Charges and Credits.