Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Useful Lives [Line Items]
Maximum Maturity Term to Be Considered Cash and Cash Equivalents	3 months
Impairment of goodwill	$ 0
Impairment of other intangible assets	0
Foreign Currency Transaction Gain (Loss), before Tax	756,000	$ 1,873,000	$ 505,000
Research and Development Expense	$ 14,765,000	$ 12,913,000	$ 12,688,000
Buildings [Member] | Minimum [Member]
Schedule of Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Buildings [Member] | Maximum [Member]
Schedule of Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	50 years
Machinery and equipment [Member] | Minimum [Member]
Schedule of Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	4 years
Machinery and equipment [Member] | Maximum [Member]
Schedule of Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	12 years