Hedging Transactions and Derivative Financial Instruments (Effect and Fair Value of Derivative Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Contracts not designated as hedging instruments | Other income (expense), net | Foreign Exchange Contracts
Derivative [Line Items]
Effect of current derivative instruments	$ (64)	$ 21
Fair Values of Derivative Instruments	(329)	21
Contracts not designated as hedging instruments | Other income (expense), net | Copper Derivatives
Derivative [Line Items]
Effect of current derivative instruments	(822)	215
Fair Values of Derivative Instruments	1,105	1,342
Contracts designated as hedging instruments | Other comprehensive income (loss) | Interest rate swap
Derivative [Line Items]
Effect of current derivative instruments	989	(180)
Fair Values of Derivative Instruments	$ 1,030	$ (180)