Property, Plant and Equipment (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Property, Plant and Equipment [Abstract]
Depreciation, Depletion and Amortization, Nonproduction	$ 13.0	$ 10.6	$ 25.4	$ 20.4
Depreciation expense on railcar assets leased to others	4.3	3.5	8.3	6.9
Amortization expense on intangible assets	$ 2.1	$ 1.6	$ 3.4	$ 3.0