Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Schedule of Segment Reporting Information, by Segment
Revenue	$ 10,611	$ 8,716
Income before taxes	1,721	1,238
Oilfield Services [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	9,918	8,122
Income before taxes	1,943	1,455
Reservoir Characterization [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	2,586	2,193
Income before taxes	672	460
Drilling [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	3,785	3,112
Income before taxes	657	465
Reservoir Production [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	3,539	2,808
Income before taxes	621	531
Eliminations and other [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	8	9
Income before taxes	(7)	(1)
Eliminations [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	(20)	(7)
Distribution Net of Eliminations [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	693	594
Income before taxes	35	22
Distribution [Member]
Schedule of Segment Reporting Information, by Segment
Revenue	713	601
Income before taxes	35	22
Corporate & other [Member]
Schedule of Segment Reporting Information, by Segment
Income before taxes	(172)	(143)
Interest income [Member]
Schedule of Segment Reporting Information, by Segment
Income before taxes	10	9
Interest expense [Member]
Schedule of Segment Reporting Information, by Segment
Income before taxes	(80)	(71)
Charges & credits [Member]
Schedule of Segment Reporting Information, by Segment
Income before taxes	$ (15)	$ (34)