Financial Instruments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
swiss franc per euro floor	1.2
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 1,700	$ 1,000
Not Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	335,800		$ 353,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	1,000
Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness	0	0
2.52% $50 Million Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Line Of Credit Facility Forecasted Borrowing Amount	$ 50,000
Derivative, Fixed Interest Rate	2.52%
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness	$ 0	$ 0
2.25% $100 Million Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Line Of Credit Facility Forecasted Borrowing Amount	$ 100,000
Derivative, Fixed Interest Rate	2.25%
Derivative Maturing in 2015 [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Value Local Currency	$ 86,000
Derivative, Forward Exchange Rate	1.21
Derivative Maturing in 2016 [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Value Local Currency	$ 67,000
Derivative, Forward Exchange Rate	1.19