Operating Segment and Sales Concentrations (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segment			3
Total revenues	$ 99,984	$ 120,746	$ 362,750	$ 344,447
Operating Income (Loss)	21,894	19,547	60,296	63,612
Asset Impairment Charges	0	0	3,554	0
Total Assets	1,497,836		1,497,836		$ 1,473,426
Gain (Loss) on Contract Termination	10,146	0	10,146	0
Corporate/Eliminations [Member]
Segment Reporting Information [Line Items]
Total Assets	(210,409)		(210,409)		(174,211)
Manufacturing [Member]
Segment Reporting Information [Line Items]
Total revenues	80,549	102,067	257,184	333,426
Operating Income (Loss)	(1,894)	3,733	4,784	20,183
Total Assets	223,949		223,949		212,508
Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Total revenues	32,427	33,440	101,352	100,992
Operating Income (Loss)	26,640	19,029	58,054	56,529
Asset Impairment Charges	0	0	(3,600)	0
Total Assets	1,415,264		1,415,264		1,375,315
Railcar Services [Member]
Segment Reporting Information [Line Items]
Total revenues	27,643	19,840	72,114	62,391
Operating Income (Loss)	2,731	1,941	7,412	6,986
Total Assets	69,032		69,032		$ 59,814
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	(5,705)	(4,603)	(14,016)	(13,828)
Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	(40,635)	(34,601)	(67,900)	(152,362)
Operating Income (Loss)	122	(553)	4,062	(6,258)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges	0	0	8,000	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	99,984	120,746	362,750	344,447
Operating Segments [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Total revenues	40,766	68,442	194,347	184,255
Operating Segments [Member] | Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Total revenues	32,427	33,440	101,352	100,992
Operating Segments [Member] | Railcar Services [Member]
Segment Reporting Information [Line Items]
Total revenues	26,791	18,864	67,051	59,200
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Intersegment Eliminations [Member] | Manufacturing [Member]
Segment Reporting Information [Line Items]
Total revenues	39,783	33,625	62,837	149,171
Intersegment Eliminations [Member] | Railcar Leasing [Member]
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Intersegment Eliminations [Member] | Railcar Services [Member]
Segment Reporting Information [Line Items]
Total revenues	852	976	5,063	3,191
Intersegment Eliminations [Member] | Eliminations [Member]
Segment Reporting Information [Line Items]
Total revenues	$ (40,635)	$ (34,601)	$ (67,900)	$ (152,362)