The percentage of net product revenue to total net revenue from the sale of goods and services as of year end.

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- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

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- Definition

The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Operating Segments and Sales, Geographic and Credit Concentrations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Revenues and Earnings (Loss) from Operations
Total revenues	$ 150,540us-gaap_SalesRevenueNet	$ 162,842us-gaap_SalesRevenueNet	$ 237,509us-gaap_SalesRevenueNet	$ 182,115us-gaap_SalesRevenueNet	$ 197,179us-gaap_SalesRevenueNet	$ 198,899us-gaap_SalesRevenueNet	$ 159,404us-gaap_SalesRevenueNet	$ 195,110us-gaap_SalesRevenueNet	$ 733,006us-gaap_SalesRevenueNet	$ 750,592us-gaap_SalesRevenueNet	$ 711,723us-gaap_SalesRevenueNet
Earnings from operations									170,058us-gaap_OperatingIncomeLoss	150,907us-gaap_OperatingIncomeLoss	121,420us-gaap_OperatingIncomeLoss
Payments to Acquire Productive Assets									327,750	184,093	205,880
Depreciation & Amortization									34,212	27,712	24,810
Total Segment assets	1,192,409us-gaap_Assets				825,609us-gaap_Assets				1,192,409us-gaap_Assets	825,609us-gaap_Assets	809,758us-gaap_Assets
Manufacturing [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									1,019,621	864,022	853,046
Earnings from operations									262,937	190,075	155,985
Manufacturing [Member]
Segment Revenues and Earnings (Loss) from Operations
Payments to Acquire Productive Assets									13,298	12,168	16,856
Depreciation & Amortization									14,472	14,504	15,239
Total Segment assets	356,720				298,951				356,720	298,951	329,346
Railcar Leasing [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									65,108	31,871	13,444
Earnings from operations									36,090	14,876	7,400
Payments to Acquire Productive Assets									307,820	162,068	185,918
Depreciation & Amortization									16,454	9,799	4,424
Total Segment assets	908,010				478,000				908,010	478,000	263,228
Railcar Services [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									67,842	72,854	65,227
Earnings from operations									10,366	14,325	10,619
Payments to Acquire Productive Assets									4,672	5,925	965
Depreciation & Amortization									2,609	2,506	2,903
Total Segment assets	52,639				52,150				52,639	52,150	49,060
Corporate [Member]
Segment Revenues and Earnings (Loss) from Operations
Payments to Acquire Productive Assets									1,960	3,932	2,141
Depreciation & Amortization									677	903	2,244
Corporate And Eliminations [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									(419,565)	(218,155)	(219,994)
Earnings from operations									(139,335)	(68,369)	(52,584)
Total Segment assets	(124,960)				(3,492)				(124,960)	(3,492)	168,124
Intersegment Eliminations [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									0	0	0
Earnings from operations									0	0	0
Intersegment Eliminations [Member] \| Manufacturing [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									419,295	217,922	219,499
Earnings from operations									126,019	54,621	35,362
Intersegment Eliminations [Member] \| Railcar Leasing [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									0	0	0
Earnings from operations									(50)	40	29
Intersegment Eliminations [Member] \| Railcar Services [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									270	233	495
Earnings from operations									67	(47)	(99)
Intersegment Eliminations [Member] \| Corporate And Eliminations [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									(419,565)	(218,155)	(219,994)
Earnings from operations									(126,036)	(54,614)	(35,292)
Operating Segments [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									733,006	750,592	711,723
Earnings from operations									170,058	150,907	121,420
Operating Segments [Member] \| Manufacturing [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									600,326	646,100	633,547
Earnings from operations									136,918	135,454	120,623
Operating Segments [Member] \| Railcar Leasing [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									65,108	31,871	13,444
Earnings from operations									36,140	14,836	7,371
Operating Segments [Member] \| Railcar Services [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									67,572	72,621	64,732
Earnings from operations									10,299	14,372	10,718
Operating Segments [Member] \| Corporate And Eliminations [Member]
Segment Revenues and Earnings (Loss) from Operations
Total revenues									0	0	0
Earnings from operations									$ (13,299)	$ (13,755)	$ (17,292)
Foreign Operations [Member]
Segment Reporting Information [Line Items]
Sales Revenue Net Percentage									4.20%	2.00%	0.90%