Industry Segments (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($) segment
Industry Segments
Number of operating segments | segment	3	3
Segment Information
Net sales	$ 2,123	$ 3,089
Pretax operating profit (loss)	(563)	(234)
Income taxes	203	19
Discontinued operations, net	438	(3)
Net income (loss)	78	(218)
Pretax Asset Impairment and Related Items	78	324
Operating segments | Oil and Gas
Segment Information
Net sales	1,275	2,009
Pretax operating profit (loss)	(485)	(266)
Net income (loss)	(485)	(266)
Operating segments | Chemical
Segment Information
Net sales	890	1,000
Pretax operating profit (loss)	214	139
Net income (loss)	214	139
Operating segments | Midstream and Marketing
Segment Information
Net sales	133	197
Pretax operating profit (loss)	(95)	(15)
Net income (loss)	(95)	(15)
Corporate and Eliminations
Segment Information
Net sales	(175)	(117)
Pretax operating profit (loss)	(197)	(92)
Income taxes	203	19
Discontinued operations, net	438	(3)
Net income (loss)	$ 444	(76)
Other charges		14
Corporate and Eliminations | Oil and Gas | Domestic and international oil and gas assets and other items member
Segment Information
Impairment charges		$ 310