Summary of Plant and Equipment by Geographic Region (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
International Long-Lived Assets by Geographic Region [Line Items]
Long lived assets	$ 372,467	$ 353,377
Domestic Operations | UNITED STATES
International Long-Lived Assets by Geographic Region [Line Items]
Long lived assets	250,866	220,397
International
International Long-Lived Assets by Geographic Region [Line Items]
Long lived assets	121,601	132,980
International | Americas, excluding U.S.
International Long-Lived Assets by Geographic Region [Line Items]
Long lived assets	12,746	12,838
International | Asia Pacific
International Long-Lived Assets by Geographic Region [Line Items]
Long lived assets	85,236	81,655
International | EMEA
International Long-Lived Assets by Geographic Region [Line Items]
Long lived assets	$ 23,619	$ 38,487