Goodwill and Intangible Assets - Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$ 565,698	$ 565,698
Impairment Charges	(1,511)	(1,511)
Accumulated Amortization	(210,994)	(199,619)
Foreign Currency Translation	3,152	1,830
Intangible assets, net	356,345	366,398
Completed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	172,431	172,431
Impairment Charges	(105)	(105)
Accumulated Amortization	(120,898)	(115,371)
Foreign Currency Translation	425	333
Intangible assets, net	51,853	57,288
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	282,744	282,744
Impairment Charges	(1,406)	(1,406)
Accumulated Amortization	(50,138)	(45,518)
Foreign Currency Translation	2,682	1,571
Intangible assets, net	233,882	237,391
Patents, Trademarks, Trade Names and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	110,523	110,523
Accumulated Amortization	(39,958)	(38,730)
Foreign Currency Translation	45	(74)
Intangible assets, net	$ 70,610	$ 71,719

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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- Definition

Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

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