Business Segment and Geographic Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Gross Trade Receivables [Member]	Dec. 31, 2011 Gross Trade Receivables [Member]	Mar. 31, 2012 Completion and Production [Member]	Mar. 31, 2011 Completion and Production [Member]	Mar. 31, 2012 Drilling and Evaluation [Member]	Mar. 31, 2011 Drilling and Evaluation [Member]	Mar. 31, 2012 Total operations [Member]	Mar. 31, 2011 Total operations [Member]	Mar. 31, 2012 Corporate and other [Member]	Mar. 31, 2011 Corporate and other [Member]
Business Segment and Geographic Information [Abstract]
Loss Contingency, Estimate of Probable Loss	$ 300
Number of business segments	2
Revenue:
Total revenue	6,868	5,282			4,290	3,172	2,578	2,110
Operating income:
Total operating income	1,023	814			1,036	660	368	230	1,404	890	(381)	(76)
Interest expense, net of interest income	(74)	(69)
Other, net	(7)	(4)
Income from continuing operations before income taxes	$ 942	$ 741
Receivables
Concentration risk (in hundredths)			43.00%	45.00%