Income Tax Effects Related to Components of Other Comprehensive Loss (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Foreign Exchange Contract [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Unrealized net gains (losses), taxes (benefits)	$ 68	$ 445

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.

Name:	us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration