Contingencies (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012 Railcar
Contingencies (Textual) [Abstract]
Number of tank cars voluntarily recertified by Company		948
Inspection cycle for tank cars in service minimum	3 years
Inspection cycle for tank cars in service maximum	5 years
Minimum possible loss	$ 6.0
Maximum possible loss	31.4
Total accruals	18.9
Highway Products litigation
Contingencies (Textual) [Abstract]
Total accruals	0
Environmental and workplace matters
Contingencies (Textual) [Abstract]
Total accruals	$ 9.2