Property, Plant and Equipment (Textual) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense			$ 23.2	$ 24.1	$ 11.5	$ 12.0
Grain
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use		$ 5.6			1.6		$ 10.9
Impairment of long-lived assets held-for-sale		$ 5.3
Rail
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use	$ 4.7
Depreciation expense on railcar assets leased to others			$ 6.0	$ 5.0	$ 12.2	$ 9.7