Revenue Sources and Concentration of Sales (Schedule of Revenue Sources and Concentration of Sales) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	$ 79,723	$ 75,946	$ 47,109	$ 87,615	$ 116,579	$ 160,598	$ 181,206	$ 219,066	$ 290,393	$ 677,449	$ 486,986
Customers Outside of US [Member]
Revenues									21,421	48,265	24,343
New railcar revenues [Member]
Revenues									103,543	565,244	444,810
Rebuild railcar revenues [Member]
Revenues									142,977	66,508
Used railcar sales [Member]
Revenues									1,238	6,177	2,772
Parts sales [Member]
Revenues									10,825	9,042	10,610
Leasing revenues [Member]
Revenues									5,776	6,118	5,468
Maintenance and Repair [Member]
Revenues									24,866	23,429	22,643
Other sales [Member]
Revenues									$ 1,168	$ 931	$ 683