Discontinued Operations - Components Comprising Net Income (Loss) from Discontinued Operations, Net (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Income (loss) from discontinued operations, net of tax	$ 0.1	$ (0.9)	$ (13.3)	$ 27.4	$ 50.4	$ (401.6)	$ 61.4	$ 46.9	$ 13.3	$ (242.9)	$ (103.8)
Disposed of by Sale | Agricultural Solutions Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Net sales									65.3	1,991.8	1,897.3
Cost of sales									(45.5)	(1,190.3)	(1,122.1)
Selling, technical, general and administrative									(37.2)	(466.4)	(531.4)
Research and development									(4.6)	(52.4)	(52.0)
Goodwill impairment									0.0	0.0	(160.0)
Gain (loss) on Arysta Sale									2.4	(450.0)	0.0
Operating (loss) profit									(19.6)	(167.3)	31.8
Other, net									9.0	11.5	(60.4)
Loss from discontinued operations, before income taxes									(10.6)	(155.8)	(28.6)
Income tax benefit (expense)									23.9	(87.1)	(75.2)
Income (loss) from discontinued operations, net of tax									13.3	(242.9)	(103.8)
Net (income) loss from discontinued operations attributable to the non-controlling interests									0.0	(3.0)	1.7
Net income (loss) from discontinued operations attributable to common stockholders									$ 13.3	$ (245.9)	(102.1)
Disposed of by Sale | Agricultural Solutions Business | Agro Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Gain (loss) on Arysta Sale											$ (160.0)