Business Segment and Geographic Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenue:
Revenue	$ 7,472		$ 7,111	$ 21,763	$ 21,213
Operating income (loss):
Operating income (loss)	1,108		954	1,994	3,178
Interest expense, net of interest income	(91)		(71)	(233)	(225)
Other, net	(12)		(6)	(37)	(30)
Income (loss) from continuing operations before income taxes	1,005		877	1,724	2,923
Charitable Contribution Tax Deductible		55
Completion and Production
Revenue:
Revenue	4,501		4,293	12,964	13,043
Operating income (loss):
Operating income (loss)	763		591	2,110	2,541
Drilling and Evaluation
Revenue:
Revenue	2,971		2,818	8,799	8,170
Operating income (loss):
Operating income (loss)	450		430	1,272	1,191
Total operations
Revenue:
Revenue	7,472		7,111	21,763	21,213
Operating income (loss):
Operating income (loss)	1,213		1,021	3,382	3,732
Corporate and other
Operating income (loss):
Operating income (loss)	$ (105)		$ (67)	$ (1,388)	$ (554)