Restructuring and Other Charges (Income) - Rollforward of Restructuring Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 17.2	$ 3.5
Changes in reserves	16.0	42.0
Cash payments	(18.6)	(25.2)
Other	0.0	(3.1)
Restructuring reserve, ending balance	14.6	17.2
DuPont Crop restructuring
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	16.2	0.0
Changes in reserves	14.3	33.2
Cash payments	(15.9)	(15.8)
Other	(0.1)	(1.2)
Restructuring reserve, ending balance	14.5	16.2
Cheminova restructuring
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0.0	1.2
Changes in reserves	0.0	0.0
Cash payments	0.0	(1.2)
Other	0.0	0.0
Restructuring reserve, ending balance	0.0	0.0
Other workforce related and facility shutdowns
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	1.0	2.3
Changes in reserves	1.7	8.8
Cash payments	(2.7)	(8.2)
Other	0.1	(1.9)
Restructuring reserve, ending balance	$ 0.1	$ 1.0