Property and Equipment (Schedule of Components of Property and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 77,282	$ 74,900
Less: accumulated depreciation and amortization	(28,977)	(23,878)
Property and equipment, net	48,305	51,022
Tanks and Terminal Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	48,536	47,797
Leasehold Improvements And Other [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	11,158	10,690
Rail and Rail Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,551	4,551
Land and Buildings [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	9,230	9,020
Trucks and Other Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	3,265	2,529
Computer Equipment, Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	495	274
Construction-In-Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 47	$ 39