Industry Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012 segment	Jun. 30, 2011	Jun. 30, 2012 segment	Jun. 30, 2011
Industry Segments
Number of reportable segments	3		3
Segment Information
Net sales	$ 5,768	$ 6,173	$ 12,036	$ 11,899
Pretax operating profit (loss)	2,207	2,930	4,906	5,389
Income taxes	(875)	(1,111)	(2,014)	(2,165)
Discontinued operations, net	(4)	(2)	(5)	142
Net income (loss)	1,328	1,817	2,887	3,366
Oil and Gas
Segment Information
Net sales	4,495	4,591	9,397	8,958
Pretax operating profit (loss)	2,043	2,624	4,547	5,092
Net income (loss)	2,043	2,624	4,547	5,092
Chemical
Segment Information
Net sales	1,172	1,325	2,320	2,490
Pretax operating profit (loss)	194	253	378	472
Net income (loss)	194	253	378	472
Midstream, Marketing and Other
Segment Information
Net sales	262	441	655	853
Pretax operating profit (loss)	77	187	208	301
Net income (loss)	77	187	208	301
Corporate and Eliminations
Segment Information
Net sales	(161)	(184)	(336)	(402)
Pretax operating profit (loss)	(107)	(134)	(227)	(476)
Income taxes	(875)	(1,111)	(2,014)	(2,165)
Discontinued operations, net	(4)	(2)	(5)	142
Net income (loss)	(986)	(1,247)	(2,246)	(2,499)
Charges on debt extinguishment				$ (163)