Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Revenues from affiliates included in manufacturing	$ 250,455	$ 103,679	$ 1,230
Revenues from affiliates included in railcar services	17,167	21,442	24,730
Selling, general and administrative costs to related party	1,122	586	582
Interest income from related parties	2,678	2,902	2,839
Other income from a related party	$ 19	$ 15	$ 16