REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenue from External Customer [Line Items]
Revenue, Percentage from Products and Service Transferred to Customers	99.00%	98.00%	99.00%	98.00%
Revenue, Remaining Performance Obligation, Amount	$ 915		$ 915		$ 826
Revenues	9,712	$ 10,764	27,836	$ 32,747
Contract with Customer, Liability, Revenue Recognized			110	100
Contract with Customer, Asset, Reclassified to Receivable			25	15
Accounts and notes receivable - Trade	4,689		4,689		4,844
Contract assets - current 1	17		17		41
Contract assets - noncurrent 2	43		43		4
Contract liabilities - current 3	310		310		193
Contract liabilities - noncurrent 4	2,004		2,004		1,607
The Dow Chemical Company [Domain]
Revenue from External Customer [Line Items]
Accounts and notes receivable - Trade	4,689		4,689		$ 4,844
U.S. & Canada
Revenue from External Customer [Line Items]
Revenues	3,391	3,932	9,885	11,937
EMEAI 1
Revenue from External Customer [Line Items]
Revenues	3,272	3,621	9,394	11,228
Asia Pacific
Revenue from External Customer [Line Items]
Revenues	2,073	2,193	5,850	6,464
Latin America
Revenue from External Customer [Line Items]
Revenues	$ 976	1,018	$ 2,707	3,118
Maximum [Member] | P21Y: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	21 years		21 years
Packaging & Specialty Plastics [Member]
Revenue from External Customer [Line Items]
Revenues	$ 4,565	5,062	$ 13,175	15,405
Packaging & Specialty Plastics [Member] | Hydrocarbons & Energy [Member]
Revenue from External Customer [Line Items]
Revenues	1,021	1,325	3,027	4,078
Packaging & Specialty Plastics [Member] | Packaging and Specialty Plastics [Member]
Revenue from External Customer [Line Items]
Revenues	3,544	3,737	10,148	11,327
Industrial Intermediates & Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenues	3,058	3,365	8,520	10,187
Industrial Intermediates & Infrastructure [Member] | Industrial Solutions [Member]
Revenue from External Customer [Line Items]
Revenues	931	1,066	2,879	3,263
Industrial Intermediates & Infrastructure [Member] | Polyurethanes & CAV [Member]
Revenue from External Customer [Line Items]
Revenues	2,124	2,295	5,632	6,914
Industrial Intermediates & Infrastructure [Member] | Other [Member]
Revenue from External Customer [Line Items]
Revenues	3	4	9	10
Performance Materials & Coatings [Member]
Revenue from External Customer [Line Items]
Revenues	2,002	2,250	5,922	6,888
Performance Materials & Coatings [Member] | Coatings and Performance Monomers [Member]
Revenue from External Customer [Line Items]
Revenues	844	900	2,438	2,749
Performance Materials & Coatings [Member] | Consumer Solutions [Member]
Revenue from External Customer [Line Items]
Revenues	1,158	1,350	3,484	4,139
Corporate Segment [Member]
Revenue from External Customer [Line Items]
Revenues	$ 87	$ 87	$ 219	$ 267