Derivatives Instruments Designated as Cash Flow Hedges - (Detail) - Cash Flow Hedging [Member] - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in OCI	$ (257)	$ (1,803)	$ 83	$ (2,010)
Cost of revenue [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	16	(74)	76	227
Selling, General and Administrative Expenses [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	12	(50)	53	180
Research and development [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	$ 19	$ (77)	$ 85	$ 278

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109978405&loc=d3e80720-113993

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580

Name:	us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration