Revenue Recognition - Disaggregation of Revenue By Major Product Category (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1,210,700,000.0
FMC Agricultural Solutions
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,107,900,000.0
FMC Agricultural Solutions | Insecticides
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	589,300,000
FMC Agricultural Solutions | Herbicides
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	385,700,000
FMC Agricultural Solutions | Fungicides
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	79,000,000
FMC Agricultural Solutions | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	53,900,000
FMC Lithium
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	102,800,000.0
FMC Lithium | Lithium Hydroxide
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	49,800,000
FMC Lithium | Butyllithium and Other Specialty Compounds
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42,400,000
FMC Lithium | Lithium Carbonate & Lithium Chloride
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 10,600,000