Industry Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Industry Segments
Number of reportable segments			3
Segment Information
Net sales	$ 6,173	$ 4,603	$ 11,899	$ 9,219
Pretax operating profit (loss)			5,389	3,765
Income taxes	(1,111)	(809)	(2,165)	(1,555)
Discontinued operations, net	(2)	(14)	142	(47)
Less: Net income attributable to noncontrolling interest		(12)		(36)
Net income (loss) attributable to common stock	1,817	1,063	3,366	2,127
Charges on debt extinguishment			163
Oil and Gas
Segment Information
Net sales			8,958	7,009
Pretax operating profit (loss)			5,092	3,764
Less: Net income attributable to noncontrolling interest				(36)
Net income (loss) attributable to common stock			5,092	3,728
Chemical
Segment Information
Net sales			2,490	1,969
Pretax operating profit (loss)			472	138
Net income (loss) attributable to common stock			472	138
Midstream, Marketing and Other
Segment Information
Net sales			853	605
Pretax operating profit (loss)			301	107
Net income (loss) attributable to common stock			301	107
Corporate and Eliminations
Segment Information
Net sales			(402)	(364)
Pretax operating profit (loss)			(476)	(244)
Income taxes			(2,165)	(1,555)
Discontinued operations, net			142	(47)
Net income (loss) attributable to common stock			$ (2,499)	$ (1,846)