Goodwill and Intangible Assets, Net - Schedule of Changes to Goodwill (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($)
Goodwill Roll Forward
Goodwill – December 31, 2018	$ 934,187
Additions	529,290
Foreign currency translation adjustments	7,888
Goodwill – March 31, 2019	$ 1,471,365

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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