Hedging - Cash Flow Hedging Instruments (Details) - Foreign currency forward contracts - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Product revenues, net \| Designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Cash Flow Hedging Instruments	$ 1,721	$ (2,461)	$ (7,438)	$ 4,291
Other (expense) income, net \| Not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Cash Flow Hedging Instruments	$ 782	$ 4,135	$ (1,832)	$ 12,958

Amount of unrealized gain (loss) related to derivatives designated as cash flow hedging instruments, recorded in results of operations to the extent that the cash flow hedge is determined to be ineffective.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration