Property, Plant and Equipment (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Total depreciation expense	$ 15,760	$ 14,572	$ 46,333	$ 42,746
Depreciation expense on leased railcars	$ 10,377	$ 8,964	29,966	$ 25,859
Tangible Asset Impairment Charges			$ 3,600