Property, Plant and Equipment (Textual) (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Capitalized interest				$ 1,700
Depreciation expense on property, plant and equipment				46,500	$ 48,300	$ 48,900
Asset impairment				6,272
Impairment of property, plant and equipment held for use				6,272	10,913	9,107
Depreciation expense on railcar assets leased to others				24,700	$ 20,000	$ 18,600
Grain
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment held for sale		$ 5,300		$ 1,600
Asset impairment		10,900
Impairment of property, plant and equipment held for use		$ 5,600
Other
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment held for use			$ 6,000
Impairment charges related to software			500
Plant Nutrient
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment held for use			$ 2,300
Rail Group
Property, Plant and Equipment [Line Items]
Impairment of property, plant and equipment held for use	$ 4,700