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The adjustment of the balance of the accrued amount for the asbestos related liability based on a review of the historical asbestos claim and resolution activity by management and their subject matter experts.

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Transaction Costs and Productivity Actions

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- Definition

Costs incurred to effect a business combination which have been expensed during the period. Such costs could include business integration costs, systems integration and conversion costs, and severance and other employee-related costs.

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No definition available.

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In a business combination achieved in stages, this element represents the amount of gain 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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- Definition

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.

+ References

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- Definition

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

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- Definition

The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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- Definition

Gain (loss) related to the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one party, or a failure to perform.

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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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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The amount of loss pertaining to the specified contingency that was charged against earnings in the period, including the effects of revisions in previously reported estimates.

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Amount of other expense (income) that is infrequent in occurrence or unusual in nature.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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SEGMENTS AND GEOGRAPHIC REGIONS Significant Items (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2016	Aug. 31, 2016	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net				$ (20)	$ 0	$ 1,617
Environmental Remediation Expense				(176)	(163)	(503)
Gain (loss) related to litigation settlement					(137)	(1,219)
Asbestos-related charge				0	0	(1,113)
Gain and post-close adjustments related to Dow Silicones ownership restructure						1,389
Gain (loss) on divestiture				0	0	(14)
Transaction Costs and Productivity Actions					(58)	(195)
Gain (Loss) on Contract Termination						(117)
Integration and separation costs				(1,074)	(716)	(349)
Restructuring, goodwill impairment and asset related charges - net				(198)	(2,742)
Loss on early extinguishment of debt				(54)	0	0
Other Nonrecurring (Income) Expense				(1,326)	(3,372)	(2,492)
Amortization of Merger-related inventory step-up				2	120	0
Performance Materials & Coatings [Member]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net				(20)
Environmental Remediation Expense						0
Gain (loss) related to litigation settlement					0	16
Asbestos-related charge						0
Gain and post-close adjustments related to Dow Silicones ownership restructure						1,389
Gain (loss) on divestiture				0
Transaction Costs and Productivity Actions					0	0
Gain (Loss) on Contract Termination						0
Integration and separation costs				0	0	0
Restructuring, goodwill impairment and asset related charges - net				(21)	(1,578)
Loss on early extinguishment of debt				0
Other Nonrecurring (Income) Expense				(41)	(1,578)	1,363
Industrial Intermediates & Infrastructure [Member]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net				0
Gain (loss) related to litigation settlement					0	(1,235)
Asbestos-related charge						0
Gain and post-close adjustments related to Dow Silicones ownership restructure						0
Transaction Costs and Productivity Actions					0	0
Gain (Loss) on Contract Termination						0
Integration and separation costs				0	0	0
Restructuring, goodwill impairment and asset related charges - net				(11)	(17)
Loss on early extinguishment of debt				0
Other Nonrecurring (Income) Expense				9	(17)	(1,319)
Packaging & Specialty Plastics [Member]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net				0
Gain (loss) related to litigation settlement					(137)	0
Asbestos-related charge						0
Gain and post-close adjustments related to Dow Silicones ownership restructure						0
Gain (loss) on divestiture				0
Transaction Costs and Productivity Actions					0	0
Gain (Loss) on Contract Termination						(117)
Integration and separation costs				0	0	0
Restructuring, goodwill impairment and asset related charges - net				(46)	(716)
Loss on early extinguishment of debt				0
Other Nonrecurring (Income) Expense				(46)	(579)	(129)
Corporate Segment [Member]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net				0
Gain (loss) related to litigation settlement					0	0
Asbestos-related charge						(1,113)
Gain and post-close adjustments related to Dow Silicones ownership restructure						0
Gain (loss) on divestiture				0
Transaction Costs and Productivity Actions					(58)	(195)
Gain (Loss) on Contract Termination						0
Integration and separation costs				(1,074)	(716)	(349)
Restructuring, goodwill impairment and asset related charges - net				(120)	(431)
Loss on early extinguishment of debt				(54)
Other Nonrecurring (Income) Expense				(1,248)	(1,198)	(2,407)
Other Environmental Matters [Domain]
Environmental Remediation Expense	$ (295)					(295)
Other Environmental Matters [Domain] \| Industrial Intermediates & Infrastructure [Member]
Environmental Remediation Expense						(1)
Other Environmental Matters [Domain] \| Packaging & Specialty Plastics [Member]
Environmental Remediation Expense						(2)
Other Environmental Matters [Domain] \| Corporate Segment [Member]
Environmental Remediation Expense						(292)
Dow Silicones Corporation
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net				(20)	0	1,617
Loss on early extinguishment of debt						15
Amortization of Merger-related inventory step-up						213
Dow Silicones Corporation \| Performance Materials & Coatings [Member]
Gain and post-close adjustments related to Dow Silicones ownership restructure			$ 1,617	(20)
Amortization of Merger-related inventory step-up		$ 213
Urethane Matters Class Action Lawsuit And Opt-Out Cases
Gain (loss) related to litigation settlement				0	0	(1,235)
Breast Implant and Other Products Liability Claims
Gain (loss) related to litigation settlement						16
Union Carbide Corporation \| Asbestos Related Matters, Defense and Processing Costs for Pending and Future Claims [Member]
Asbestos-related charge						(1,009)
Union Carbide Corporation \| Asbestos Related Matters, Pending and Future Claims
Asbestos-related charge						(104)
MEGlobal
Gain (loss) on divestiture				20
MEGlobal \| Industrial Intermediates & Infrastructure [Member]
Gain (loss) on divestiture				$ 20
AgroFresh
Gain (loss) on divestiture						20
Chlorine Value Chain
Gain (loss) on divestiture					7	6
Loss Contingency, Loss in Period						33
Chlorine Value Chain \| Performance Materials & Coatings [Member]
Gain (loss) on divestiture					0
Chlorine Value Chain \| Industrial Intermediates & Infrastructure [Member]
Gain (loss) on divestiture					0
Chlorine Value Chain \| Packaging & Specialty Plastics [Member]
Gain (loss) on divestiture					0
Chlorine Value Chain \| Corporate Segment [Member]
Gain (loss) on divestiture					$ 7
AFSI
Equity Method Investment, Other than Temporary Impairment						143
Other Nonoperating Income (Expense) [Member] \| Performance Materials & Coatings [Member]
Gain (loss) on divestiture						0
Other Nonoperating Income (Expense) [Member] \| Industrial Intermediates & Infrastructure [Member]
Gain (loss) on divestiture						0
Other Nonoperating Income (Expense) [Member] \| Packaging & Specialty Plastics [Member]
Gain (loss) on divestiture						0
Other Nonoperating Income (Expense) [Member] \| Corporate Segment [Member]
Gain (loss) on divestiture						$ (14)