Derivatives Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative [Line Items]
Proceeds from Issuance of Warrants			$ 12,376,000	$ 0
Convertible due 2021 - Bond Hedge, Initial Fair Value	$ 27,975,000		27,975,000
Convertible Debt Conversion Feature, Initial Fair Value	(34,480,000)		(34,480,000)
Foreign currency forward contracts
Derivative [Line Items]
Notional amount of derivatives, matured during period	59,663,000	$ 38,020,000	171,889,000	100,657,000
Selling, General and Administrative Expenses | Foreign currency forward contracts
Derivative [Line Items]
Gain recognized in income	271,000	172,000		113,000
Loss on derivative			$ (106,000)
Minimum
Derivative [Line Items]
Derivative, percentage of forcasted transactions with currency rate exposure			50.00%
Maximum
Derivative [Line Items]
Derivative, percentage of forcasted transactions with currency rate exposure			90.00%
Cash Flow Hedging [Member]
Derivative [Line Items]
Gain (Loss)	798,000	(116,000)	$ 1,250,000	1,070,000
Cash Flow Hedging [Member] | Sales [Member]
Derivative [Line Items]
Gain recognized in income	1,417,000		2,826,000
Loss on derivative		(1,087,000)		(1,865,000)
Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative [Line Items]
Gain recognized in income		$ 971,000		$ 2,935,000
Loss on derivative	(619,000)		(1,576,000)
Convertible Subordinated Debt | Convertible Senior Notes at 5.00% February 2021 [Member]
Derivative [Line Items]
Debt Instrument, Face Amount	$ 150,000,000		$ 150,000,000
Interest rate (as a percent)	5.00%		5.00%