Major Customers (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue, Major Customer [Line Items]
Total product sales	$ 42,530,000	$ 47,854,000
Total tooling sales	2,938,000	1,745,000
Total sales	45,468,000	49,599,000
Navistar [Member]
Revenue, Major Customer [Line Items]
Total product sales	10,885,000	12,808,000
Total tooling sales	5,000	15,000
Total sales	10,890,000	12,823,000
Volvo [Member]
Revenue, Major Customer [Line Items]
Total product sales	8,854,000	13,629,000
Total tooling sales	422,000	1,019,000
Total sales	9,276,000	14,648,000
Paccar [Member]
Revenue, Major Customer [Line Items]
Total product sales	6,152,000	9,714,000
Total tooling sales	2,221,000	635,000
Total sales	8,373,000	10,349,000
Yamaha [Member]
Revenue, Major Customer [Line Items]
Total product sales	5,446,000	5,233,000
Total tooling sales	0	0
Total sales	5,446,000	5,233,000
Other Customers [Member]
Revenue, Major Customer [Line Items]
Total product sales	11,193,000	6,470,000
Total tooling sales	290,000	76,000
Total sales	$ 11,483,000	$ 6,546,000