COMMITMENTS AND CONTINGENT LIABILITIES COMMITMENTS AND CONTINGENT LIABILITIES (Commercial Creditor Issues) (Details) - USD ($) $ in Millions	Jun. 01, 2016	Sep. 30, 2016
Commercial Creditor Issues [Domain]
Estimated Litigation Liability, Current		$ 106
Commercial Creditor Issues [Domain] \| June 1, 2004 Breast Implant and Other Products Liability Claims [Member]
Payments made to Commercial Creditors for Principal and Interest		1,500
Minimum [Member] \| Commercial Creditor Issues [Domain] \| June 1, 2004 Breast Implant and Other Products Liability Claims [Member]
Loss Contingency, Estimate of Possible Loss		106
Maximum [Member] \| Commercial Creditor Issues [Domain] \| June 1, 2004 Breast Implant and Other Products Liability Claims [Member]
Loss Contingency, Estimate of Possible Loss		$ 352
Dow Corning Corporation [Member]
Indemnification Percentage of Future Losses Associated with Certain Pre-closing Liabilities	50.00%
Maximum Amount of Indemnified Losses Which may be Recovered until May 31, 2018 for certain pre-closing liabilities	$ 1,500
Maximum Amount of Indemnified Losses Which may be Recovered Between May 31, 2018 and May 31, 2023 for certain pre-closing liabilities	$ 1,000

Indemnification Percentage of Future Losses Associated with Certain Pre-closing Liabilities

No definition available.

Name:	dow_IndemnificationPercentageofFutureLossesAssociatedwithCertainPreclosingLiabilities
Namespace Prefix:	dow_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum Amount of Indemnified Losses Which may be Recovered Between May 31, 2018 and May 31, 2023 for certain pre-closing liabilities

+ References

No definition available.

+ Details

Name:	dow_MaximumAmountofIndemnifiedLossesWhichmaybeRecoveredBetweenMay312018andMay312023forcertainpreclosingliabilities
Namespace Prefix:	dow_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum Amount of Indemnified Losses Which may be Recovered until May 31, 2018 for certain pre-closing liabilities

+ References

No definition available.

+ Details

Name:	dow_MaximumAmountofIndemnifiedLossesWhichmaybeRecovereduntilMay312018forcertainpreclosingliabilities
Namespace Prefix:	dow_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Payments made to Commercial Creditors for Principal and Interest

+ References

No definition available.

+ Details

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

- Definition

Carrying amount of reserve for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs, which is expected to be paid within one year of the date of the statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 55
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6396582&loc=d3e15243-108350

+ Details

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

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=dow_CommercialCreditorIssuesDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationStatusAxis=dow_June12004BreastImplantandOtherProductsLiabilityClaimsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=dow_DowCorningCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: