COMMITMENTS AND CONTINGENT LIABILITIES (Guarantees) (Table and Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Guarantees [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum future payments	$ 4,739	$ 5,042
Guarantor obligations, recorded liability	$ 106	$ 160
Final expiration	2021	2021
Residual Value Guarantees [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum future payments	$ 910	$ 951
Guarantor obligations, recorded liability	$ 118	$ 123
Final expiration	2025	2024
Total Guarantees [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum future payments	$ 5,649	$ 5,993
Guarantor obligations, recorded liability	$ 224	283
Sadara [Member]
Guarantor Obligations [Line Items]
Equity Method Investment, Ownership Percentage	35.00%
Sadara [Member] \| Guarantee of Indebtedness of Others [Member]
Guarantor Obligations [Line Items]
Guarantor obligations, maximum future payments	$ 4,400
Total Project Financing [Member] \| Sadara [Member] \| Long Term Debt entered into by Equity Method Investee
Guarantor Obligations [Line Items]
Project Financing, Maximum Borrowing Capacity	12,500
Construction Loans [Member] \| Sadara [Member] \| Long Term Debt entered into by Equity Method Investee
Guarantor Obligations [Line Items]
Amount Drawn, Total Project Financing	$ 11,800	$ 10,500

Amount Drawn, Total Project Financing

No definition available.

Name:	dow_AmountDrawnTotalProjectFinancing
Namespace Prefix:	dow_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Final expiration year of guarantees of the reporting entity.

+ References

No definition available.

+ Details

Name:	dow_GuaranteeObligationsYearOfFinalExpiration
Namespace Prefix:	dow_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under project financing facility for Sadara project.

+ References

No definition available.

+ Details

Name:	dow_ProjectFinancingMaximumBorrowingCapacity
Namespace Prefix:	dow_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_GuaranteeObligationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_GuaranteesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=dow_ResidualValueGuaranteesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=dow_TotalGuaranteesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=dow_SadaraMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_GuaranteeOfIndebtednessOfOthersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dow_TotalProjectFinancingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=dow_LongTermDebtenteredintobyEquityMethodInvesteeDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: