Summary of Significant Accounting Policies (Property Plant and Equipment Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 411,454	$ 393,541
Less: accumulated depreciation	(288,971)	(281,328)
Property, Plant and Equipment, Net, Total	122,483	112,213
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	4,550	4,619
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	39,263	37,234
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	226,076	212,225
Office Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	9,708	9,929
Tooling [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	76,933	75,620
Information Technology [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	32,410	27,179
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	614	872
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	4,588	2,799
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 17,312	$ 23,064