Supplementary Data - Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ in Millions	3 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
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 454.7	$ 464.7	$ 456.7	$ 459.8	$ 478.4	$ 488.5	$ 501.6	$ 492.5
Gross profit from continuing operations	191.3	205.7	193.0	198.3	202.2	209.6	214.7	211.1
Net loss from continuing operations	74.4	(6.0)	14.7	(3.5)	(14.2)	(4.3)	(49.6)	(8.9)
Net income (loss) from discontinued operations	0.1	(0.9)	(13.3)	27.4	50.4	(401.6)	61.4	46.9
Net income (loss)	$ 74.5	$ (6.9)	$ 1.4	$ 23.9	$ 36.2	$ (405.9)	$ 11.8	$ 38.0
Earnings (loss) per share
Basic from continuing operations (in dollars per share)	$ 0.30	$ (0.02)	$ 0.06	$ (0.02)	$ (0.05)	$ (0.02)	$ (0.17)	$ (0.04)
Basic from discontinued operations (in dollars per share)	0	(0.01)	(0.05)	0.11	0.18	(1.40)	0.21	0.17
Basic attributable to common stockholders (in dollars per share)	0.30	(0.03)	0.01	0.09	0.13	(1.42)	0.04	0.13
Diluted from continuing operations (in dollars per share)	0.29	(0.02)	0.06	(0.02)	(0.05)	(0.02)	(0.17)	(0.04)
Diluted from discontinued operations (in dollars per share)	0	(0.01)	(0.05)	0.11	0.18	(1.40)	0.21	0.17
Diluted attributable to common stockholders (in dollars per share)	$ 0.29	$ (0.03)	$ 0.01	$ 0.09	$ 0.13	$ (1.42)	$ 0.04	$ 0.13
Held-for-sale | Agricultural Solutions Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Estimated impairment loss					$ 74.0	$ 376.0