Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 1,310	$ 1,359	$ 2,687	$ 2,274
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on investments	(14)	(9)	(39)	8
Cumulative translation adjustments	(470)	387	(94)	626
Pension and other postretirement benefit plans	124	101	250	203
Derivative instruments	118	(39)	124	(89)
Total other comprehensive income (loss)	(242)	440	241	748
Comprehensive income	1,068	1,799	2,928	3,022
Comprehensive income (loss) attributable to noncontrolling interests, net of tax	(1)	40	27	93
Comprehensive income attributable to The Dow Chemical Company	$ 1,069	$ 1,759	$ 2,901	$ 2,929

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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