REVENUE (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Revenue from External Customer [Line Items]
Revenue, Percentage from Products and Service Transferred to Customers	98.00%	98.00%	98.00%	99.00%
Revenue, Remaining Performance Obligation, Amount	$ 851		$ 851		$ 977
Revenues	13,885	$ 8,354	25,767	$ 18,124
Contract with Customer, Liability, Revenue Recognized			180	80
Contract with Customer, Asset, Reclassified to Receivable				25
Accounts and notes receivable - Trade	6,456		6,456		4,839
Contract assets - current	51		51		58
Contract assets - noncurrent	28		28		11
Contract liabilities - current 1	211		211		349
Contract liabilities - noncurrent	1,970		1,970		1,915
The Dow Chemical Company
Revenue from External Customer [Line Items]
Accounts and notes receivable - Trade	6,456		6,456		$ 4,839
U.S. & Canada
Revenue from External Customer [Line Items]
Revenues	4,927	2,944	8,955	6,494
EMEAI 1
Revenue from External Customer [Line Items]
Revenues	5,102	2,711	9,431	6,122
Asia Pacific
Revenue from External Customer [Line Items]
Revenues	2,479	1,932	4,844	3,777
Latin America
Revenue from External Customer [Line Items]
Revenues	$ 1,377	767	$ 2,537	1,731
Maximum [Member] | P20Y: 2021-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	20 years		20 years
Packaging & Specialty Plastics [Member]
Revenue from External Customer [Line Items]
Revenues	$ 7,121	4,001	$ 13,203	8,610
Packaging & Specialty Plastics [Member] | Hydrocarbons & Energy [Member]
Revenue from External Customer [Line Items]
Revenues	2,008	787	3,759	2,006
Packaging & Specialty Plastics [Member] | Packaging and Specialty Plastics [Member]
Revenue from External Customer [Line Items]
Revenues	5,113	3,214	9,444	6,604
Industrial Intermediates & Infrastructure [Member]
Revenue from External Customer [Line Items]
Revenues	4,215	2,417	7,822	5,462
Industrial Intermediates & Infrastructure [Member] | Industrial Solutions [Member]
Revenue from External Customer [Line Items]
Revenues	1,201	894	2,250	1,948
Industrial Intermediates & Infrastructure [Member] | Polyurethanes & CAV [Member]
Revenue from External Customer [Line Items]
Revenues	3,012	1,520	5,568	3,508
Industrial Intermediates & Infrastructure [Member] | Other [Member]
Revenue from External Customer [Line Items]
Revenues	2	3	4	6
Performance Materials & Coatings [Member]
Revenue from External Customer [Line Items]
Revenues	2,465	1,855	4,588	3,920
Performance Materials & Coatings [Member] | Coatings and Performance Monomers [Member]
Revenue from External Customer [Line Items]
Revenues	1,010	766	1,865	1,594
Performance Materials & Coatings [Member] | Consumer Solutions [Member]
Revenue from External Customer [Line Items]
Revenues	1,455	1,089	2,723	2,326
Corporate Segment [Member]
Revenue from External Customer [Line Items]
Revenues	$ 84	$ 81	$ 154	$ 132