Property, Plant and Equipment (Details Textual) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation expense on property, plant and equipment		$ 48,900	$ 46,400	$ 40,500
Impairment of property, plant and equipment		9,107	285	3,090
Depreciation expense on railcar assets leased to others		$ 18,600	$ 17,600	$ 14,200
Retail
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment	$ 6,000
Impairment charges related to software	500
Plant Nutrient
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment	$ 2,300