Property, Plant and Equipment (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Depreciation expense on property, plant and equipment	$ 27.4	$ 20.4	$ 18.7
Depreciation expense on railcar assets leased to others	$ 15.9	$ 13.8	$ 14.0