Commitments and Contingencies (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 31, 2015	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Build-to-Suit Lease
Operating Leased Assets [Line Items]
Term of leasing contract	15 years
Other long term liabilities | Build-to-Suit Lease
Operating Leased Assets [Line Items]
Financing obligation		$ 23.1	$ 24.3	$ 24.7
Other current liabilities | Build-to-Suit Lease
Operating Leased Assets [Line Items]
Financing obligation		1.5	$ 1.4	1.4
Capital Addition Purchase Commitments
Operating Leased Assets [Line Items]
Amount remaining under long-term commitment obligation		105.9
Amount prepaid under long-term commitment obligation		$ 10.5
Legal Claim 2015 | Plant Nutrient
Operating Leased Assets [Line Items]
Loss contingency reserve				$ 2.2