Property, Plant and Equipment (Details Textual) (USD $) In Millions, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Property, Plant and Equipment [Abstract]
Depreciation expense on property, plant and equipment	$ 19.3	$ 15.0	$ 20.4
Depreciation expense on railcar assets leased to others	$ 11.9	$ 10.2	$ 13.8