Acquisitions and Divestitures Divestiture (Dow Brazil Corn Seed Business) (Details) $ in Millions	Sep. 30, 2017 USD ($)
Dow AgroSciences' Corn Seed Business [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration	$ 1,100

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.

No definition available.

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Balance Type:	na
Period Type:	duration