SEGMENTS AND GEOGRAPHIC REGIONS Significant Items (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gain (Loss) Related to Litigation Settlement		$ 205		$ 137
Charges related to separation, distribution and tax matters agreements		(144)
Gain (loss) on divestiture		(49)	$ 0	7
Transaction Costs and Productivity Actions			(54)	(58)
Integration and separation costs		(1,013)	(1,074)	(716)
Restructuring, goodwill impairment and asset related charges - net		(3,219)	(198)	(2,742)
Loss on early extinguishment of debt		(102)	(54)	0
Accrual for Environmental Loss Contingencies, Revision in Estimates	$ 399	(399)
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties		39
Other Nonrecurring (Income) Expense		(4,682)	(1,326)	(3,372)
Packaging & Specialty Plastics [Member]
Gain (Loss) Related to Litigation Settlement		170		137
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net			0
Charges related to separation, distribution and tax matters agreements		0
Gain (loss) on divestiture		0	0	0
Transaction Costs and Productivity Actions			0	0
Integration and separation costs		0	0	0
Restructuring, goodwill impairment and asset related charges - net		(439)	(46)	(716)
Loss on early extinguishment of debt		0
Accrual for Environmental Loss Contingencies, Revision in Estimates	5	(5)
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties		0
Other Nonrecurring (Income) Expense		(274)	(46)	(579)
Industrial Intermediates & Infrastructure [Member]
Gain (Loss) Related to Litigation Settlement		0		0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net			0
Charges related to separation, distribution and tax matters agreements		0
Gain (loss) on divestiture			20	0
Transaction Costs and Productivity Actions			0	0
Integration and separation costs		0	0	0
Restructuring, goodwill impairment and asset related charges - net		(1,175)	(11)	(17)
Loss on early extinguishment of debt		0
Accrual for Environmental Loss Contingencies, Revision in Estimates	8	(8)
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties		0
Other Nonrecurring (Income) Expense		(1,188)	9	(17)
Performance Materials & Coatings [Member]
Gain (Loss) Related to Litigation Settlement		0		0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net			(20)
Charges related to separation, distribution and tax matters agreements		0
Gain (loss) on divestiture		0	0	0
Transaction Costs and Productivity Actions			0	0
Integration and separation costs		0	0	0
Restructuring, goodwill impairment and asset related charges - net		(1,076)	(21)	(1,578)
Loss on early extinguishment of debt		0
Accrual for Environmental Loss Contingencies, Revision in Estimates	50	(50)
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties		0
Other Nonrecurring (Income) Expense		(1,126)	(41)	(1,578)
Corporate Segment [Member]
Gain (Loss) Related to Litigation Settlement		35		0
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net			0
Charges related to separation, distribution and tax matters agreements		(144)
Gain (loss) on divestiture		(44)	0	7
Transaction Costs and Productivity Actions			(54)	(58)
Integration and separation costs		(1,013)	(1,074)	(716)
Restructuring, goodwill impairment and asset related charges - net		(529)	(120)	(431)
Loss on early extinguishment of debt		(102)
Accrual for Environmental Loss Contingencies, Revision in Estimates	$ 336	(336)
Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties		39
Other Nonrecurring (Income) Expense		(2,094)	(1,248)	(1,198)
Dow Silicones Corporation
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain (Loss), Net		0	(20)	$ 0
MEGlobal
Gain (loss) on divestiture			$ 20
MEGlobal \| Industrial Intermediates & Infrastructure [Member]
Gain (loss) on divestiture		$ (5)

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Amount of expense (reversal of expense) which increases (decreases) the accrual for environmental loss contingencies from revisions in estimates to existing obligations. Excludes changes related to business acquisitions, divestitures, or currency movement.

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

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