Operating Segment and Sales and Credit Concentrations (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segment	3
Total revenues	$ 176,180	$ 263,776
Earnings from operations	40,697	60,015
Total Assets	1,423,516		$ 1,525,074
Corporate/Eliminations [Member]
Segment Reporting Information [Line Items]
Total Assets	(91,956)		5,293
Manufacturing [Member]
Segment Reporting Information [Line Items]
Total revenues	147,423	305,542
Earnings from operations	22,686	70,438
Total Assets	245,117		272,721
Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Total revenues	32,768	24,585
Earnings from operations	19,675	14,764
Total Assets	1,211,790		1,190,180
Railcar Services [Member]
Segment Reporting Information [Line Items]
Total revenues	20,579	17,482
Earnings from operations	3,508	2,867
Total Assets	58,565		$ 56,880
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Earnings from operations	(4,508)	(4,350)
Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	(24,590)	(83,833)
Earnings from operations	(664)	(23,704)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	176,180	263,776
Operating Segments [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Total revenues	123,792	221,811
Operating Segments [Member] | Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Total revenues	32,768	24,585
Operating Segments [Member] | Railcar Services [Member]
Segment Reporting Information [Line Items]
Total revenues	19,620	17,380
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0
Intersegment Eliminations [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Total revenues	23,631	83,731
Intersegment Eliminations [Member] | Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0
Intersegment Eliminations [Member] | Railcar Services [Member]
Segment Reporting Information [Line Items]
Total revenues	959	102
Intersegment Eliminations [Member] | Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (24,590)	$ (83,833)