Financial Instruments, Risk Management and Fair Value Measurements (Details) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2017 USD ($) swap_agreement	Dec. 31, 2016 USD ($) swap_agreement	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of interest rate derivatives held | swap_agreement			0	0
Estimated fair value of debt			$ 3,250.6	$ 1,964.9
Carrying amount of debt			3,185.6	1,893.0
Impairment loss on indefinite-lived intangible asset			42.1		$ 9.3
FMC Agricultural Solutions [Member]
Segment Reporting Information [Line Items]
Impairment loss on indefinite-lived intangible asset	$ 1.0	$ 1.0	$ 1.0	$ 1.0