Industry Segments (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) segment	Jun. 30, 2015 USD ($) segment
Segment Information
Number of operating segments | segment			3	3
Net sales	$ 2,531	$ 3,469	$ 4,654	$ 6,558
Pretax operating profit (loss)	(232)	504	(795)	270
Income taxes	96	(324)	299	(305)
Discontinued operations, net	(3)	(4)	435	(7)
Net income (loss)	(139)	176	(61)	(42)
Operating segments | Oil and Gas
Segment Information
Net sales	1,625	2,342	2,900	4,351
Pretax operating profit (loss)	(117)	355	(602)	89
Net income (loss)	(117)	355	(602)	89
Operating segments | Chemical
Segment Information
Net sales	908	1,030	1,798	2,030
Pretax operating profit (loss)	88	136	302	275
Net income (loss)	88	136	302	275
Operating segments | Midstream and Marketing
Segment Information
Net sales	141	294	274	491
Pretax operating profit (loss)	(58)	87	(153)	72
Net income (loss)	(58)	87	(153)	72
Corporate and Eliminations
Segment Information
Net sales	(143)	(197)	(318)	(314)
Pretax operating profit (loss)	(145)	(74)	(342)	(166)
Income taxes	96	(324)	299	(305)
Discontinued operations, net	(3)	(4)	435	(7)
Net income (loss)	$ (52)	$ (402)	$ 392	(478)
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