Segment Information - Schedule of Segment Reporting Information, by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information [Line Items]
Revenue	$ 11,608		$ 10,498		$ 33,360		$ 30,648
Income before taxes	2,231		1,798		6,521		5,204
Operating Segments
Segment Reporting Information [Line Items]
Revenue	11,608		10,498		33,360		30,648
Income before taxes	2,496		2,084		6,740		6,005
Operating Segments | Reservoir Characterization
Segment Reporting Information [Line Items]
Revenue	3,232		2,835		8,996		8,066
Income before taxes	983		799		2,616		2,183
Operating Segments | Drilling
Segment Reporting Information [Line Items]
Revenue	4,415		4,035		12,820		11,772
Income before taxes	894		727		2,429		2,102
Operating Segments | Production
Segment Reporting Information [Line Items]
Revenue	4,024		3,655		11,708		10,896
Income before taxes	707		537		1,888		1,746
Eliminations And Other
Segment Reporting Information [Line Items]
Revenue	(63)		(27)		(164)		(86)
Income before taxes	(88)		21		(193)		(26)
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Revenue
Income before taxes	(179)		(177)		(529)		(516)
Interest Income
Segment Reporting Information [Line Items]
Revenue		[1]		[1]		[2]		[2]
Income before taxes	6	[1]	8	[1]	15	[2]	24	[2]
Interest expense
Segment Reporting Information [Line Items]
Revenue		[3]		[3]		[4]		[4]
Income before taxes	(92)	[3]	(85)	[3]	(277)	[4]	(241)	[4]
Charges And Credits
Segment Reporting Information [Line Items]
Revenue
Income before taxes			$ (32)		$ 572		$ (68)

[1] Excludes interest income included in the segment results ($3 million in 2013; $— million in 2012).

[2] Excludes interest income included in the segment results ($5 million in 2013; $— million in 2012).

[3] Excludes interest expense included in the segment results ($6 million in 2013; $3 million in 2012).

[4] Excludes interest expense included in the segment results ($17 million in 2013; $5 million in 2012).