Amount of revenue earned from products sold or services provided under the terms of a contract, including, but not limited to, government contracts and construction contracts, classified as other.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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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

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- Details

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Major Customers (Details) - USD ($)	3 Months Ended												12 Months Ended
Major Customers (Details) - USD ($)	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Major customers:
Total product sales	$ 37,900,000	$ 37,593,000	$ 36,794,000	$ 36,336,000	$ 33,465,000	$ 33,816,000	$ 36,813,000	$ 42,530,000	$ 43,492,000	$ 44,243,000	$ 53,514,000	$ 47,854,000	$ 148,623,000	$ 146,624,000	$ 189,103,000
Total tooling sales	1,165,000	901,000	10,574,000	410,000	15,607,000	7,520,000	2,193,000	2,938,000	3,072,000	3,806,000	1,342,000	1,745,000	13,050,000	28,258,000	9,965,000
Total net sales	$ 39,065,000	$ 38,494,000	$ 47,368,000	$ 36,746,000	$ 49,072,000	$ 41,336,000	$ 39,006,000	$ 45,468,000	$ 46,564,000	$ 48,049,000	$ 54,856,000	$ 49,599,000	161,673,000	174,882,000	199,068,000
Product sales
Major customers:
Total net sales													148,623,000	146,624,000	189,103,000
Tooling sales
Major customers:
Total net sales													13,050,000	28,258,000	9,965,000
Navistar
Major customers:
Total net sales													39,768,000	41,750,000	56,415,000
Navistar \| Product sales
Major customers:
Total net sales													39,609,000	39,756,000	50,169,000
Navistar \| Tooling sales
Major customers:
Total net sales													159,000	1,994,000	6,246,000
Volvo [Member]
Major customers:
Total net sales													35,716,000	49,970,000	55,125,000
Volvo [Member] \| Product sales
Major customers:
Total net sales													27,627,000	29,520,000	53,525,000
Volvo [Member] \| Tooling sales
Major customers:
Total net sales													8,089,000	20,450,000	1,600,000
Paccar
Major customers:
Total net sales													29,413,000	27,716,000	34,430,000
Paccar \| Product sales
Major customers:
Total net sales													26,481,000	24,235,000	33,452,000
Paccar \| Tooling sales
Major customers:
Total net sales													2,932,000	3,481,000	978,000
Yamaha [Member]
Major customers:
Total net sales													17,137,000	16,205,000	16,766,000
Yamaha [Member] \| Product sales
Major customers:
Total net sales													17,137,000	16,205,000	16,766,000
Yamaha [Member] \| Tooling sales
Major customers:
Total net sales													0	0	0
BRP [Member]
Major customers:
Total net sales													13,663,000	12,494,000	7,082,000
BRP [Member] \| Product sales
Major customers:
Total net sales													13,024,000	10,870,000	7,082,000
BRP [Member] \| Tooling sales
Major customers:
Total net sales													639,000	1,624,000	0
Other customers
Major customers:
Total net sales													25,976,000	26,747,000	29,250,000
Other customers \| Product sales
Major customers:
Total net sales													24,745,000	26,038,000	28,109,000
Other customers \| Tooling sales
Major customers:
Total net sales													$ 1,231,000	$ 709,000	$ 1,141,000