Benefit Plans - Summary of Contributions to Retirement Plans (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Contribution to retirement plans	$ 289	$ 330
US Employees [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to retirement plans	156	202
Foreign Employees [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to retirement plans	$ 133	$ 128

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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-Publisher FASB
-Name Accounting Standards Codification
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Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration