Property, Plant and Equipment and Railcars on Leases, net (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Components of property, plant and equipment
Property, plant and equipment, net	$ 173,069	$ 177,051
Operations / Corporate: [Member]
Components of property, plant and equipment
Property, plant and equipment, gross	422,913	421,435
Less accumulated depreciation	(249,844)	(244,384)
Property, plant and equipment, net	173,069	177,051
Railcar Leasing [Member]
Components of property, plant and equipment
Property, plant and equipment, gross	1,052,266	996,422
Less accumulated depreciation	(96,644)	(88,412)
Property, plant and equipment, net	955,622	908,010
Buildings [Member] | Operations / Corporate: [Member]
Components of property, plant and equipment
Property, plant and equipment, gross	183,086	182,970
Machinery and equipment [Member] | Operations / Corporate: [Member]
Components of property, plant and equipment
Property, plant and equipment, gross	232,035	232,171
Land [Member] | Operations / Corporate: [Member]
Components of property, plant and equipment
Property, plant and equipment, gross	4,329	4,328
Construction in process [Member] | Operations / Corporate: [Member]
Components of property, plant and equipment
Property, plant and equipment, gross	$ 3,463	$ 1,966