Financial Instruments Financial Instruments Textual (Details) $ in Thousands, € in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) Rate	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Rate	Sep. 30, 2015 USD ($)	Sep. 30, 2016 EUR (€) Rate	Dec. 31, 2015 USD ($)
Derivative [Line Items]
swiss franc per euro floor	1.2		1.2		1.2
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ 500
Designated as Hedging Instrument [Member] | 3.24% $100 Million Interest Rate Swap [Member]
Derivative [Line Items]
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness	$ 0		0
Line Of Credit Facility Forecasted Borrowing Amount	$ 50,000		$ 50,000
Derivative, Fixed Interest Rate | Rate	2.52%		2.52%		2.52%
Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative [Line Items]
Notional Value Local Currency	$ 67,000		$ 67,000		€ 20.6
Derivative, Notional Amount	23,100		23,100			$ 73,000
Unrealized Gain (Loss) on Foreign Currency Derivatives, Net, before Tax	0	$ (6,100)	500	$ 18,100
Gain (Loss) on Foreign Currency Cash Flow Hedge Ineffectiveness	0		0
Designated as Hedging Instrument [Member] | ERROR in label resolution.
Derivative [Line Items]
Line Of Credit Facility Forecasted Borrowing Amount	$ 100,000		$ 100,000
Derivative, Fixed Interest Rate | Rate	2.25%		2.25%		2.25%
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 319,400		$ 319,400			318,700
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 0	$ 4,700	$ (700)	$ (4,800)
Derivative Maturing in 2015 [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative [Line Items]
Derivative, Forward Exchange Rate	1.21		1.21		1.21
Derivative, Notional Amount						86,000
Maturing in 2016 [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative [Line Items]
Notional Value Local Currency						$ 67,000
Derivative, Forward Exchange Rate	1.19		1.19		1.19