Property, Plant and Equipment (Details Textual) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 11.9	$ 12.0	$ 36.0	$ 35.7
Depreciation expense on railcar assets leased to others		$ 5.2	$ 4.7	$ 14.9	$ 14.0
Retail
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets	$ 6.0
Capitalized computer software, impairments	0.5
Plant Nutrient
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets	$ 2.3