Industry Segments (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($) segment
Segment Information
Number of operating segments \| segment			3	3
Net sales	$ 3,060	$ 2,531	$ 6,017	$ 4,654
Pre-tax operating profit (loss)	792	(232)	987	(795)
Income taxes	(285)	96	(363)	299
Discontinued operations, net		(3)		435
Net income (loss)	507	(139)	624	(61)
Gain on sale of assets	512		512	138
Operating segments \| Oil and Gas
Segment Information
Net sales	1,848	1,625	3,742	2,900
Pre-tax operating profit (loss)	627	(117)	847	(602)
Net income (loss)	627	(117)	847	(602)
Operating segments \| Chemical
Segment Information
Net sales	1,156	908	2,224	1,798
Pre-tax operating profit (loss)	230	88	400	302
Net income (loss)	230	88	400	302
Gain on sale of assets			31
Operating segments \| Chemical \| Occidental Tower in Dallas
Segment Information
Gain on sale of properties			57
Operating segments \| Midstream and Marketing
Segment Information
Net sales	270	141	481	274
Pre-tax operating profit (loss)	119	(58)	72	(153)
Net income (loss)	119	(58)	72	(153)
Operating segments \| Midstream and Marketing \| Equity investment
Segment Information
Non-cash fair value gain	88		88
Corporate and Eliminations
Segment Information
Net sales	(214)	(143)	(430)	(318)
Pre-tax operating profit (loss)	(184)	(145)	(332)	(342)
Income taxes	(285)	96	(363)	299
Discontinued operations, net		(3)		435
Net income (loss)	(469)	$ (52)	(695)	$ 392
South Texas operations \| Domestic oil and gas assets
Segment Information
Gain on sale of assets	$ 510		$ 510

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

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