SUPPLEMENTARY INFORMATION Summary of Sundry Income (Expense) - Net (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Sundry income (expense) - net	$ 268	$ 22	$ 144	$ 1,369
Foreign Currency Transaction Gain (Loss), before Tax	(5)	(37)	(61)	(102)
Interest income	27	0	74	0
Net gain on sales of assets, businesses and investments			474	179
Ownership Restructure of Equity Interest in Acquiree, Remeasurement Gain	0	0	0	2,445
Nova patent infringement award [Member]
Gain (Loss) Related to Litigation Settlement	0	0	137	0
Bayer CropScience v. Dow AgroSciences [Member]
Gain (Loss) Related to Litigation Settlement	0	0	(469)	0
Urethane Matters Class Action Lawsuit And Opt-Out Cases [Member]
Gain (Loss) Related to Litigation Settlement	0	0	0	(1,235)
Chlorine Value Chain [Domain]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	0	(33)	0	(33)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Global Ethylene Acrylic Acid Copolymers and Ionomers [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	227	0	227	0
Scenario, Previously Reported [Member]
Sundry income (expense) - net		(4)		1,305
Interest income		26		64
Net gain on sales of assets, businesses and investments				0
Impact to Sundry income (expense) [Member]
Net gain on sales of assets, businesses and investments	$ 10	$ 45	$ 147	$ 130

In a business combination achieved in stages, this element represents the amount of net gain (loss) recognized by the entity as a result of remeasuring to fair value the equity interest in the acquiree it held before the business combination.

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Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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