Major Customers (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	$ 36,336,000	$ 42,530,000
Contracts Revenue	410,000	2,938,000
Revenue, Net	36,746,000	45,468,000
Navistar [Member]
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	9,257,000	10,885,000
Contracts Revenue	18,000	5,000
Revenue, Net	9,275,000	10,890,000
Volvo [Member]
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	5,235,000	8,854,000
Contracts Revenue	31,000	422,000
Revenue, Net	5,266,000	9,276,000
Paccar [Member]
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	5,462,000	6,152,000
Contracts Revenue	190,000	2,221,000
Revenue, Net	5,652,000	8,373,000
Yamaha [Member]
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	5,312,000	5,446,000
Contracts Revenue	0	0
Revenue, Net	5,312,000	5,446,000
BRP [Member] [Member]
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	4,711,000	3,949,000
Contracts Revenue	23,000	0
Revenue, Net	4,734,000	3,949,000
Other Customers [Member]
Revenue, Major Customer [Line Items]
Sales Revenue, Goods, Net	6,359,000	7,244,000
Contracts Revenue	148,000	290,000
Revenue, Net	$ 6,507,000	$ 7,534,000