Summary of Sundry Income (Expense) - Net (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Sundry income (expense) - net	$ 53	$ (1)	$ (28)	$ 68
Gain (Loss) on Extinguishment of Debt	0	(44)	(86)	(44)
Gain (Loss) Related to Litigation Settlement	6		6
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		(44)		(44)
Charges related to separation, distribution and tax matters agreements		(127)		(127)
Other Operating Income (Expense) [Member]
Charges related to separation, distribution and tax matters agreements		(52)
Corporate Segment [Member]
Gain (Loss) on Extinguishment of Debt	0	(44)	(86)	(44)
Gain (Loss) Related to Litigation Settlement	0		0
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		(44)		(44)
Charges related to separation, distribution and tax matters agreements		(127)		(127)
Corporate Segment [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		(58)
Packaging & Specialty Plastics [Member]
Gain (Loss) on Extinguishment of Debt	0	0	0	0
Gain (Loss) Related to Litigation Settlement	6		6
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		0		0
Charges related to separation, distribution and tax matters agreements		0		0
The Dow Chemical Company [Domain]
Sundry income (expense) - net	51	109	$ (31)	$ 178
The Dow Chemical Company [Domain] \| Corporate Segment [Member]
Gain (Loss) on Extinguishment of Debt		(44)
The Dow Chemical Company [Domain] \| Corporate Segment [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 14
The Dow Chemical Company [Domain] \| Packaging & Specialty Plastics [Member]
Gain (Loss) Related to Litigation Settlement	$ 6

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

+ References

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Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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