Summary of Sundry Income (Expense) - Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Sundry income (expense) - net	$ 83	$ (444)
Gain on sales of other assets and investments	32	4
Interest income	28	0
Non-operating pension and other postretirement benefit plan net credit 1	18	1
Foreign exchange losses	(16)	(26)
Bayer CropScience v. Dow AgroSciences [Member]
Loss related to Bayer CropScience arbitration matter 1	$ 0	(469)
Scenario, Previously Reported [Member]
Sundry income (expense) - net		(470)
Interest income		$ 25