Changes in Carrying Value of Goodwill (Detail) $ in Thousands	6 Months Ended
Jun. 30, 2019 USD ($)
Goodwill [Line Items]
Balance as of December 31, 2018	$ 326,735
Cumulative translation adjustment	(106)
Acquisition of C Technologies, Inc.	142,881
Balance as of June 30, 2019	$ 469,510

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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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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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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