Segment Information - Schedule of Segment Reporting Information, by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Income before taxes	$ 2,673	$ 1,779	$ 4,291	$ 3,406
Revenue	11,182	10,341	21,752	20,150
Operating Segments [Member] | Reservoir Characterization [Member]
Segment Reporting Information [Line Items]
Income before taxes	908	749	1,633	1,384
Revenue	3,014	2,714	5,764	5,231
Operating Segments [Member] | Drilling [Member]
Segment Reporting Information [Line Items]
Income before taxes	804	727	1,534	1,374
Revenue	4,292	3,977	8,405	7,737
Operating Segments [Member] | Production [Member]
Segment Reporting Information [Line Items]
Income before taxes	625	601	1,181	1,209
Revenue	3,926	3,718	7,684	7,241
Operating Segments [Member] | Oilfield Services [Member]
Segment Reporting Information [Line Items]
Income before taxes	2,278	2,039	4,243	3,922
Revenue	11,182	10,341	21,752	20,150
Eliminations [Member] | Eliminations & other [Member]
Segment Reporting Information [Line Items]
Income before taxes	(59)	(38)	(105)	(45)
Revenue	(50)	(68)	(101)	(59)
Corporate, Non-Segment [Member] | Corporate & other [Member]
Segment Reporting Information [Line Items]
Income before taxes	(181)	(169)	(348)	(339)
Revenue
Segment Reconciling Items [Member] | Interest income [Member]
Segment Reporting Information [Line Items]
Income before taxes	4	7	9	16
Revenue
Segment Reconciling Items [Member] | Interest expense [Member]
Segment Reporting Information [Line Items]
Income before taxes	(92)	(76)	(185)	(156)
Revenue
Segment Reconciling Items [Member] | Charges & credits [Member]
Segment Reporting Information [Line Items]
Income before taxes	664	(22)	572	(37)
Revenue