Divestitures and Other Transactions Divestitures and Other Transactions - Divested Ag Business Results of Operations (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill impairment charge	$ 0			$ 1,102
(Loss) income from discontinued operations after income taxes		$ 1,077	$ (323)	717	$ (674)
Specialty Products Disposal [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill impairment charge		1,102	0	1,102	0
(Loss) income from discontinued operations before income taxes		(1,237)	535	(798)	1,002
(Loss) income from discontinued operations after income taxes		1,243	$ (267)	902	(559)
Equity Method Investment, Other than Temporary Impairment		63		63
Divested Ag Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) income from discontinued operations before income taxes					(10)
(Loss) income from discontinued operations after income taxes		80		80	$ 5
Other discontinued operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) income from discontinued operations after income taxes		86		86
Industrial Biosciences [Member] | Specialty Products Disposal [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill impairment charge		$ 1,102		$ 1,102