Operating Segment and Sales and Credit Concentrations (Details 2)	3 Months Ended		6 Months Ended
	Jun. 30, 2013 customer	Jun. 30, 2012 customer	Jun. 30, 2013 customer	Jun. 30, 2012 customer	Dec. 31, 2012 customer
Manufacturing [Member]
Segment Reporting Information [Line Items]
Percentage of revenue from affiliates	12.50%	7.10%	23.40%	3.20%
Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Percentage of revenue from affiliates	0.00%	0.00%	0.00%	0.00%
Number of customers that made up more than 10% of consolidated revenues (in customers)	0	0	0	0
Number of customers that made up more than 10% of consolidated accounts receivable (in customers)	0		0		0
Railcar Services [Member]
Segment Reporting Information [Line Items]
Percentage of revenue from affiliates	2.90%	3.80%	2.60%	3.30%
Number of customers that made up more than 10% of consolidated revenues (in customers)	0	0	0	0
Number of customers that made up more than 10% of consolidated accounts receivable (in customers)	0		0		0
Sales Revenue, Segment [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Percentage of total consolidated revenues from significant customers	64.80%	54.30%	63.30%	56.10%
Accounts Receivable [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Percentage of total consolidated accounts receivable from significant customers	40.90%		40.90%		35.10%