Hedging (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($) Derivatives	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)
Derivatives, Fair Value [Line Items]
Maximum Length of Time Hedged in Cash Flow Hedge	2 years
Derivative, Number of New Instruments During Period | Derivatives	6
Derivative, New Instruments During Period, Notional Amount	$ 3,600
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(164)	$ 29
Unrealized loss on hedge instruments	(509)	(177)	$ (177)	$ (25)	$ (527)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(168)	473
Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(164)
Hedge Loss Recognized in Other Comprehensive Income (Loss)	(332)	502
Cost of Sales [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(57)	10
Research and Development Expense [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(80)	14
Selling, General and Administrative Expenses [Member]
Derivatives, Fair Value [Line Items]
Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	(27)	$ 5
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Derivative Instrument Assets at Fair Value	133		508
Other Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value	0		0
Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	100
Notional Amount of Foreign Currency Cash Flow Hedge Derivatives	$ 9,073		$ 13,018
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Number of New Instruments During Period | Derivatives	18
Derivative, New Instruments During Period, Notional Amount	$ 11,600