Components of Accumulated Other Comprehensive Loss (Parenthetical) (Detail) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Unrealized net gains (losses), taxes (benefits)	$ (405)	$ (34)	$ (405)	$ 68	$ 445
Revaluation of tax effects	$ 149	$ 149	$ 149

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.

No definition available.

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