Contingencies (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended		9 Months Ended
	Sep. 30, 2011 Railcar	Jun. 30, 2011 Railcar	Sep. 30, 2011
Contingencies (Textual) [Abstract]
Date Company received a letter from the Federal Railroad Administration ("FRA") containing a rail worthiness directive pertaining to a specific design of tank cars		In June 2011
Number of tank cars manufactured for transport of poison inhalation hazard materials		948
Number of tank cars Federal Railroad Administration received notification regarding potential leaks around the man way nozzles		5
Number of recently manufactured tank cars removed from service pursuant to directive		100
Number of randomly selected tank cars removed from service		67
Number of tank cars manufactured since 2006 less the number of manufactured tank cars removed from service pursuant to defective		848
Potential costs and expenses incurred for compliance with directive			cannot be reasonably estimated
Recertification Process Schedule Description			through September, 2014
Inspection cycle for tank cars in service minimum			3 years
Inspection cycle for tank cars in service maximum			5 years
Reserve for probable and estimable liabilities with respect to the investigations, assessments and remedial responses	$ 7.7		$ 7.7
Number of tank cars voluntarily recertified by Company	948